illustrations are done for 8 puzzles it is mentioned with the text add cyan 20-2pt box arround with brainteaser icon Problems

Transcription

1 illustrations are done for 8 puzzles it is mentioned with the text add cyan 20-2pt box arround with brainteaser icon Problems 1. From a basket of mangoes when counted in twos theres was one extra, counted in threes there were two extra, counted in forms there were three extras, counted in fives there were from extra, counted in sixes there were five extra. But counted in sevens there were no extra. How many mangoes were there in basket in the least? 2. A boy was asked to find the L.C.M. of 3, 5, 12 and another number. But while calculating he wrote 21 instead of 12 and yet came with the correct answer. What could be the fourth number? 3. There were five pieces of cloth of lengths 15m, 21m, 36m, 42m, 48 metres. But all of them could be measured in whole units a measuring rod. what couldbe the largest length of the rod? 4. A man hired a chanter for a month and agreed to pay him at the rate of Rs. 100/- per day he worked. They agreed that the contract could be broken on any day during the month in which case the full payment that is due to the chaun... by that day would be made. The man put the all the wages due to the chanuff. by that day would be made. The man put the all the month wages due to the chauff. for the entire in five different packs in such a way that he could pay him on an day of the month without opening any of the packets. How much did the packets have? 5. There are three cans. One of them holds exactly 10 litrs. of milk and is full. The other two can hold 7 litres and three ltrs. respectively. There is no graduate mark in the can. A customer asks for 5 ltrs. of milk. How would you give him. What he asks? He would be satisfied by eye estimate. 7. Which two digits number when added to 27 is reversed? 8. Cement mortar was being prepared by mixing cement to sand in the ratio of 1:6 volume by volume. In a cement mortar of 42 units of volume how much more cement need to beadded to enrich the mortar to the ratio to 2:9.

2 9. In a solution of common salt in water the ratio of salt to water was 3:70 weight per weight. If we evaporate one 100 grams of water from one of this solution, what will be the ratio of the salt to water? 10. Half a swam of bees went to collect honey from a mustard field. Three fourth 11. Fifteen children are sitting in a circle. They are asked to pass a hand knchief to the child immediately after his or her left... the following The game shops once the handkerchief returns to child it started from. This can be written as follows Here we see that every child gets the hand kerchief. What would happen if the handknerchief were passed to the left leaving two children in between? Would every child get the handkerchief? What if we leave three children in between. What do you see? In which cases every child gets the handkerchief and which cases not? Try the same game with 16, 17, 18, 19, 20 children. What do you see? 12. Take two numbers 9 and 16. Divide 9 by 16. Divide 9 by 16 to get the recmainder. What is the remainder when 2 9 is divided by 16, 3 9 divided by 16, 7 9 divided by 16, 8 9 divided by divided by 16. List the remainders. Take the number 12 and 14. List the remainders of 12, 12 2, 12 3, 12 4, 12 4, 12 5, 12 6, 12 7, 12 8, 12 9, 12 10, 12 11, divided by 14. Do you see any difference between above two cases? 13. You have been given two cans with capacities 9 and 5 respectively. There is no graduate mark on the cans nor is eye estimate possible. How can you collect 3 litres of water from a tap. (you are allowed to pour out water from the can). If the cans had capacities 8 and 6 litres respectively could you colelct 5 litres? 14. The area of the east wall of a room is 108 sq.m. to that of the north wall is 135 square ft. and the area of the floor is 180 square feet. Find the

3 height of the room. 15. If we subtract 4 from the digit at theunits place of a two digit number and add 4 to the digit at the ten s places then the resulting number is doubled. Find the number. 16. Two boatmen start simultaneously from the opposite shores of a river and they cross each other after 45 minutes of their starting from the respective shores. They rowed to the till they reached the opposite shore and returend immediately after reaching teh shores. Whebn will they cross each other again. 17. Three hens lay three eggs in three days. Two many eggs would nine hens lay nine days? 18. Find a four digit number which is a perfect square and its last two digits are repeated. 19. Three girls a stair case. One girls climbs down two steps at one go. The second girl three steps at one go and the third climbs down four steps. They started together from the begining of the stair case leaving their foot marks. They all had their foot marks together at the end of the stair case. In how many steps would there be only onefoot marks? 20. A group soldies were asked to fall in line in rows of three. It was found that there was one soldier extra. Then they were asked to stand in rows of five. It was found there were 2 soldiers too many. They were asked to stand in rows of seven. It was there were three soldiers which could not be adjust. At least how many soldiers were there in the group? 21. If we write 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ina row to create the number which digit will be at the 900th place taken from the left. 22. There was a number ending in 7 like * * * * 7 If we bought 7 to the leftmost point then the resulting number is tripled. Find the least such number.

4 23. Get 100 using four 9 s andsame of the symbols like +,,, etc. 24. What will be in the units place of (27 times)? 25. How many digits would be the product (30 times)? 26. A man would be5 minutes late at his destination if herides his bike at 30 km. per hour. But he would be 10 minutes early if he rides at the speed of 40 km. per hour. What is the distance of his destination from when he starts? 27. Sadhna left her house for play between 3:00 pm and 4 pm. When she returned home the hands of the clocks were reversed. When did she leave for play. 28. In a race in covering a distance A beats B by 12 metres, C by 20 mtrs., and B beats C by 10 mtrs. What could be the distance they covered during the race? 29. The ratio of speeds of two vehicles is 2:3. If the first vehicle covers 50 km. is 3 hours what would the second vehicle cover in 2 hours? 30. The ratio of income to expenditure of Mr. Natarajan is 7:5. If he saves Rs. 2000/- a month what could be his income? 31. An employee suffer a cut of 20% in his wage. By what percent would his wage be increased so that he gets back his old wages. 32. A shopkeeper hiked the cost price of an article by 20% and offered 10% rebate on the hiked price. Does he make a profit or incur a loss in the process? Calculate his profit or loss. 33. The ratio of the length to breadth of a lawn is 3:5. It cost Rs. 3200/- to fence it at the rate of Rs. 2/- a meter. What would be the cost of developing the lawn at the rate of Rs.10/- per square metre If one counts one for the thumb two for the index finger three for the middle finger, four for the ring finger, five for the little finger and continues counting by counting back wards, six for the ring fingerseven for the middle

5 finger, eight for the index finger 9 for the thumb ten for the index finger, eleven for the middle finger twelve for the... figner thirteenfor the little finger the fourteen for the ring finger and so on which figner will be counted as one thousand? 35. Three frinds plucked some mangoes from a mango grove and collected them together in a pile and took nap after that. After some time one of the friends woke up and divided the mangoes into three equal numbers. There was one mango extra. He gave it to a monkey nearby took one part for himself and slept again. Next the second friend get up unaware of what has happened divided the rest of the mangoes into three equal share4s. There was an extra mango. He gave it to themonkey took one share for himself and slept again. Next the third friend get up not knowing what happened divided the mangoes into three equal shares. There was an extra mango. He gave it to the monkey took one share for himself and went to sleep again. After some time all of them got up together to find mangoes. How many mangoes did the friends pluck initially? 36. Two brothers went selling some goats in a market. They sold each goat for as many rupees as many goats they had. They tried to divide the money in the following way. First the elder brother took Rs.10/- from the bag that certained the money earned by selling the goats. Next the younger brother took Rs.10/- from the bag. Next the elder brother took Rs.10/- from the bag. They continued like this when the turn of the younger brother came he found there was less than Rs.10/- in the bag. To compensate for the short fall the elder brother gave his scarf to the younger brother. What was the cost of the scarf? 32. Which of the shaded regions is a greater area? 33. A man a plot of land which was of the shape of a square. He sold a quarter of it from a corner as shown in the side. His four children wanted to share the land in sch a way that each plot alloted to each of them would of same area and same shape.

6 34. Ten saplings are to be planted in straight lines in such way that each line has exactly four of them. 35. Count the total number of triangles formed by nine matchsticks as shown. Remove two match sticks to get exactly two triangles. 36. What will be the next number in the sequence a) 1, 5, 9, 13, 17, 21, b) 2, 7, 12, 17, 22, c) 2, 6, 12, 20, 30 d) 1, 2, 3, 5, 8, 13, e) 1, 3, 6, 10, Find the sum Do not try to find LCM of the denomintaor. 38. Which is larger Find the area of

7 40. A cube is painted on all its face red. Let if be cut into 125 small cubes as shown. How many of the little cubes won t have colour on them fices? How many of them would have only one face coloured? 41. Three brothers had 9 cowsyielding 1 litre, 2 litres, 3 litres, 4 litres, 5 litres, 6 litres, 7 litres, 8 litres and 9 litres of milk respectively. The wanted to distribute the cows among themselves such that each brother got 3 cros and get the same amount of milk as the both. 42. A teacher had three pupils Ram, Rahim and Alice she brought five caps three of them were red and two blue. She showed them the caps first. Then she asked them to shut their eyes. She put one cap on each pupils need and hid the rest two. She asked Ram to look at the colour of caps on heads of Rahim and Alice andtell the colour of the cap on his head. Ram after looking said he could not. The teacher asked the same thing of Rahim. He too could not guess the colour of the cap on his head. At this Alicesaid she could tell the colour of her cap even without opening her eyes. What was the colour of her cap? How could she come to that conclusion. 43. Find the area of the triangle BEF Heena and Sheila were given 50 ml of syrup each in of their glass to be diluted with water and drunk. Heena added 100ml water where as Sheila added 75ml of water to their respective glasses. They started drinking the mix. At the end both of them left 20ml each in their respective glasses. Who do you think has taken more sugar? 46. Leena and Meena have been given one buckets of water each. They soaked their clothes in two other buckets of detergent solution. They had same volume of clothes soaked in same volume of detergent solutions. After scrubbing and squeezing out the deteregents this came for rinsing. Leena poured half the bucket of water into the squeezed clothes and then after rinsing poured out clothes left after rinsing. Then she poured the other half of the bucket and rinsed. Meena poured only 1 th of the 4

8 bucket into the squeezing clothes, rinsed poured out the liquid. Then she poured 1 th of the bucket rinsed and poured on the liquid. This she 4 continued till he supply of bucket of water was finished. Whose clothes are better cleaned for the detergent?