Aptitude and Reasoning Questions

Number of students behind Manoj in rank = (31 - 7) = 24.

So, Manoj is 25th from the bottom.

Number of students behind Satya in rank = (31 - 11) = 20.

So, Satya is 21st from the bottom.

Let the weight of the empty tin = w

(2 - w) = weight of the cookies; and one quarter of the cookies weigh (2 - w)/4

One quarter of the cookies + tin = 0.8 = w + (2 - w)/4

Multiply through by 4; 3.2 = 4w + 2 - w

1.2 = 3w; w = 0.4

Speed of boat in still water = 1/2 (12 + 6) = 9 kmph.

For solving this problem first we would break the whole range in 5 sections

1) From 1 to 9
Total number of zero in this range = 0

2) From 10 to 99
Total possibilities = 9*1 = 9 ( here 9 is used for the possibilities of a non zero integer)

3) From 100 to 999 - three type of numbers are there in this range
a) x00 b) x0x c) xx0 (here x represents a non zero number)
Total possibilities
for x00 = 9*1*1 = 9, hence total zeros = 9*2 = 18
for x0x = 9*1*9 = 81, hence total zeros = 81
similarly for xx0 = 81
total zeros in three digit numbers = 18 + 81 +81 = 180

4) From 1000 to 9999 - seven type of numbers are there in this range
a)x000 b)xx00 c)x0x0 d)x00x e)xxx0 f)xx0x g)x0xx
Total possibilities
for x000 = 9*1*1*1 = 9, hence total zeros = 9*3 = 27
for xx00 = 9*9*1*1 = 81, hence total zeros = 81*2 = 162
for x0x0 = 9*1*9*1 = 81, hence total zeros = 81*2 = 162
for x00x = 9*1*1*9 = 81, hence total zeros = 81*2 = 162
for xxx0 = 9*9*9*1 = 729, hence total zeros = 729*1 = 729
for xx0x = 9*9*1*9 = 729, hence total zeros = 729*1 = 729
for x0xx = 9*1*9*9 = 729, hence total zeros = 729*1 = 729
total zeros in four digit numbers = 27 + 3*162 + 3*729 = 2700
thus total zeros will be 0+9+180+2700+4 (last 4 is for 4 zeros of 10000)
= 2893

As given
200 cats kill 200 mice in 200 days
1 cats kill 1 mouse in 200 days
Then
8 cats kill 8 mice in 200 days.

The pattern is + 1*1,+ 2*2, +3*3, + 4*4,+ 5*5,+ 6*6, . . . . . . .
So missing term is 56+36=92

A = P(1 + rt/100)

So, A= 3P (it becomes triples)

3P = P(1 + 8r/100)→r = 25%

Now, when t = 20

⇒A = P(1 + 25*20/100)

⇒A = P(1+ 5)⇒A = 6P

So, it becomes 6 times.