4
Q:

# 8 years ago there were 5 members in the Arthur's family and then the average age of the family  was 36 years. Mean while Arthur got married and gave birth to a child. Still the average age of his family is same now. What is the age of his wife at the time of his child's birth was.If the difference between the age of her  child and herself was 26 years.

 A) 25 years B) 26 years C) 20 years D) can't be determined

Explanation:

Since we know that the difference b/w the age of any two persons remains always constant, while the ratio of their ages gets changed as the time changes.

so, if the age of his child be x (presently)

Then the age of  wife be x + 26 (presently)

Thus the total age = x + ( x + 26) = 32  [$\because$252-220 =32]

=> x = 3

Therefore, The age of her child is 3 years and her self  is 29 years. Hence her age at the time of the birth of her child was 26 years.

Q:

The average weight of 45 passengers in a bus is 52 kg. 5 of them whose average weight is 48 kg leave the bus and other 5 passengers whose average weight is 54 kg join the bus at the same stop. What is the new average weight of the bus?

 A) 54.21 kgs B) 51.07 kgs C) 52.66 kgs D) 53.45 kgs

Explanation:

Given total number of passengers in the bus = 45

First average weight of 45 passengers = 52 kgs

Average weight of 5 passengers who leave bus = 48

Average weight of passengers who joined the bus = 54

Therefore, the net average weight of the bus is given by

15 886
Q:

12 boys decided to constribute Rs. 750 each to an Orphange. Suddenly few of them boys dropped out and consequently the rest had to pay Rs. 150 more. Then the number of boys who dropped out?

 A) 4 B) 6 C) 2 D) 3

Explanation:

Total money decided to contribute = 750 x 12 = 9000

Let 'b' boys dropped

The rest paid 150/- more

=> (12 - b) x 900 = 9000

=> b = 2

Hence, the number of boys who dropped out is 2.

13 1115
Q:

P, Q, R, S, T and U are six consecutive odd numbers and their average is 52. What is the product of P and U ?

 A) 2212 B) 2154 C) 2349 D) 2679

Explanation:

Let x, x+2, x+4, x+6, x+8 and x+10 are six consecutive odd numbers.

Given that their average is 52

Then, x + x+2 + x+4 + x+6 + x+8 + x+10 = 52×6

6x + 30 = 312

x = 47

So Product = 47 × 57 = 2679

12 1145
Q:

19 friends went to a restaurant for a combined weekend dinner party. 13 of them spent Rs. 79 each on their dinner and the rest spent Rs. 4 more than the average expenditure of all the 19. What was the total money spent by them?

 A) Rs. 1398.96 B) Rs. 1457.09 C) Rs. 1662.35 D) Rs. 1536.07

Explanation:

Let average expenditure was Rs. R

13 x 79 + 6x(R + 4) = 19R

=> R = Rs. 80.84

Total money = 19 x 80.84 = Rs. 1536.07.

19 1075
Q:

The average age of a class is 19 years. While the average age of girls is 18 and that of boys is 21. If the number of girls in the class is 16, Find the number of Boys in the class?

 A) 12 B) 10 C) 8 D) 6

Explanation:

Let the number of boys = x

From the given data,

=> [21x + 16(18)]/(x+16) = 19

=> 21x - 19x = 19(16) - 16(18)

=> 2x = 16

=> x = 8

Therefore, the number of boys in the class = 8.

13 1251
Q:

The mean of 100 observations is 40. It is found that an observation 84 was misread as 48. Then the correct mean is ?

 A) 40.36 B) 41.24 C) 41.92 D) 42.05

Explanation:

Given,

mean of 100 observations is 40

=> Total of 100 observations = 40 x 100 = 4000

=> Difference = 84 - 48 = 36

=> Now, new total of 100 observations = 4000 + 36 = 4036

Correct Mean = 4036/100 = 40.36

15 1473
Q:

The average marks of a student in 7 subjects is 85. His average marks in 6 subjects except English is 83. What is his marks in English ?

 A) 97 B) 98 C) 92 D) 93

Explanation:

Marks in English  = 85×7 – 83×6

= 595 – 498

= 97

17 1663
Q:

Navaneet has thrice the money Poonam has and Poonam has 25% more money than Hebah. If the average money of the three is Rs. 350, What is the amount that Navaneet has ?

 A) Rs. 175 B) Rs. 220.75 C) Rs. 218.55 D) Rs. 656.25

Explanation:

Assume Hebah has Rs. M

Since 25% more money at Poonam

=> Money at Poonam = M + (25% of M)

=> Money at Poonam = M + 0.25M = Rs. 1.25M

Money with Navaneet is thrice the money with Poonam,

=> Money at Navaneet = 3(1.25M) = Rs. 3.75M

Now, sum of all Money = (M + 1.25M + 3.75M) = Rs. 6M

But given the average of the money is Rs. 350

=> 6M/3 = 350

=> 2M = 350

=> M = 350/2 = Rs. 175

=> Amount of money Navaneet has = Rs. 3.75M = 3.75 x 175 = Rs. 656.25.