Periyar University 2008 B.E Electronics

=>the box color left out is "green", which is allotted to the only box left, the 1 which has yellow ball.

Ans: green





84) A bag contains 20 yellow balls, 10 green balls, five white balls, eight black balls, and one red ball. How many minimum balls 1 should pick out so that to make sure the he gets at lowest two balls of identical color.

Sol: suppose he picks five balls of all various colors then when he picks up the 6th one, it must match any on of the previously drawn ball color. Thus he must pick six balls

Ans: he should pick six balls totally.





85) WHAT IS THE NUMBER OF ZEROS AT THE END OF THE PRODUCT OF THE NUMBERS FROM one TO 100?

Sol: For every five in unit place 1 zero is added

so ranging from one to 100 there are 10 nos like 5,15,25,..,95 which has five in unit place.

Similarly for every no divisible by 10 1 zero is added in the ans so ranging from one to 100 , 11 zeros are added

For 25, 50, 75 three extra zeros are added

So total no of zeros are 10+11+3=24





86) There are 2 numbers in the ratio 8:9. If the smaller of the 2 numbers is increased by 12 and the larger number is decreased by 19 thee the ratio of the 2 numbers is 5:9.

obtain the larger number?

Sol: 8x: 9x initially

8x+ 12: 9x - 19 = 5x: 9x

8x+12 = 5x

-> x = 4

9x = 36 (NOT SURE ABOUT THE ANSWER)




87) There are 3 various boxes A, B and C. Difference ranging from weights of A and B is three kgs. And ranging from B and C is five kgs. Then what is the maximum sum of the differences of all possible combinations when 2 boxes are taken every time

Sol: A-B = 3

B-c = 5

A-c = eight so sum of diff = 8+3+5 = 16 kgs




88) A and B are shooters and having their examination. A and B fall short of 10 and two shots respectively to the qualifying mark. If every of them fired at lowest 1 shot and even by adding their total score together, they fall short of the qualifying mark, what is the qualifying mark?

Sol: Because every had at lowest one shot done so 10 + one = 11

And nine + two = 11

So the ans is 11




89) A, B, C, and D tells the subsequent times by looking at their watches. A tells it is three to 12. B tells it is three past 12 . C tells it is 12:2. D tells it is half a dozen too soon to 12. No 2 watches show the identical time. The difference ranging from the watches is 2,3,4,5 respectively. Whose watch indicates maximum time?

Earning:   Approval pending.