14
Q:

# Five years ago, the average age of A, B, C and D was 45 years. With E Joining them now, the average of all the five is 49 years. The age of E is?

Q:

The ratio of present ages of Hema and Chinnu is 13:17. Four years ago the ratio of their ages was 11:15. What will be the ratio of their ages six years hence ?

 A) 3 : 7 B) 7 : 9 C) 4 : 5 D) 1 : 3

Answer & Explanation Answer: C) 4 : 5

Explanation:

Let their present ages be 13x and 17x.
Then, 13x-4/17x-4 = 11/15.
Solving this, we get x = 2.
Required ratio = 13x2 + 6/17x2 + 6 = 32/40 = 4/5.

1 65
Q:

The average age of 80 boys in a class is 15. The average age of group of 15 boys in the class is 16 and the average of another 25 boys in the class is 14. What is the average age of the remaining boys in the class ?

 A) 12.24 yrs B) 13.25 yrs C) 16 yrs D) 15.25 yrs

Answer & Explanation Answer: D) 15.25 yrs

Explanation:

Total ages of 80 boys = 15 x 80 = 1200 yrs.
Total age of 16 boys = 15 x 16 = 240 yrs
Total age of 25 boys = 14 x 25 = 350 yrs.
Average age of remaining boys = 1200 - (240+350) / 80 - (25+15) = 610/41 = 15.25 yrs.

1 23
Q:

Two boys are playing on a ground. Both the boys are less than 10 years old. Age of the younger boy is equal to the cube root of the product of the age of the two boys. If we place the digit representing the age of the younger boy to the left of the digit representing the age of the elder boy, we get the age of the father of the younger boy. Similarly, we place the digit representing the age of the elder boy to the left of the digit representing the age of the younger boy and divide the figure by 2, we get the age of the mother of the younger boy. The mother of the younger boy is younger than his father by 3 years. Then, what are the ages of elder and younger boys ?

 A) E = 15 & Y = 3 B) E = 14 & Y = 12 C) E = 40 & Y = 22 D) E = 4 & Y = 2

Answer & Explanation Answer: D) E = 4 & Y = 2

Explanation:

Let the the age of the elder boy = E

Let the the age of the younger boy = Y

Given that Y = cube root of EY

=> $\inline \fn_jvn Y^{3}$ = EY => E = $\inline \fn_jvn Y^{2}$ .....(1)
By the condition of number replacement the age of the father is YE

The Mother's age = EY/2

But she is 3 years less than father => EY/2 + 3 = YE
2YE = EY + 6 ......(2)

Then now from the given options we can identify which satisfies the all the conditions.

Here Y =2 and E = 4 satisfies all the conditions.

1 23
Q:

5 years ago Sushma was 5 times as old as her Son. 5 years hence her age will be 8 less than three times the corresponding age of her Son. Find their ages ?

 A) 24 and 13 years B) 48 and 24 years C) 35 and 11 years D) 33 and 15 years

Answer & Explanation Answer: C) 35 and 11 years

Explanation:

Let the age of sushma be x and
the age of her son is y
Then five years before x-5=5(y-5) ...(1)
Five years hence x+5 = 3(y+5)-8 .....(2)

By soving (1) & (2), we get
5y - 15 = 3y + 7
y = 11 => x = 35

Therefore, the age of Sushma = 35 and her son = 11.

1 20
Q:

The ratio of present ages of X and Y is 4:5. Which of the following can't be the ratio of ages of X and Y, 20 years ago ?

 A) 2 : 5 B) 8 : 15 C) 9 : 10 D) 3 : 5

Answer & Explanation Answer: C) 9 : 10

Explanation:

The ratio of X and Y ages at present is 4:5.

Then, the ratio 20 years ago will not be more than the ratio at present.

So, from the options 9:10 is not satifying => its ratio is 0.9 which is greater than presnt ratio of 0.8.