AIEEE Questions

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Number of non - negative integral solutions =n+r-1 Cr-1 = C223 = 253 

504/42 × 7 - 63 + 28 = 84 – 63 + 28 = 49

Hence option 5 is correct.

Brother

Justification: Daughter of uncle's father -- Uncle's sister -- Mother;
Mother's son -- Brother.

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

1) Man's wife. = 1
2) Man's 4 son's wives. = 4
3) Man's daughter. = 1
4) 4 son's has each one daughter. = 4
Therefore, total number of female members in the family = 1+4+1+4 = 10.

Ratio of girls and boys = 100% : 75% = 4:3

Difference is 1 unit = 35

So, 3 units = 35 x 3 = 105

If 20% absent, that’s mean 80% present.

So, present boys = 80% of 105 = 80×105100 = 84