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Q:

# The average age of a group of 10 students is 15 years. When 5 more students join the group, the average age increase by 1 year. The average age of the new students is?

Q:

The present average age of a family of five members is 26 years. If the present age of the youngest member in the family is ten years, then what was the average age of the family at the time of the birth of the youngest member ? (Assume no death occurred in the family since the birth of the youngest)

 A) 19 years B) 16 years C) 18 years D) 20 years

Explanation:

Present total age of the members = 26(5) = 130 years.

Present age of the youngest member = 10 years

Present total age of the remaining four members = 130 -10 = 120 years

Their average age at the time of the birth of the youngest member = $\inline \fn_jvn \small \frac{[120 - (4 x 10)] }{4}$ = 30 - 10 = 20 years.

1 18
Q:

Eight years ago, Ajay's age was 4/3 times that of Vijay. Eight years hence, Ajay's age will be 6/5 times that of Vijay. What is the present age of Ajay ?

 A) 41 yrs B) 40 yrs C) 37 yrs D) 33 yrs

Explanation:

Let the present ages of Ajay and Vijay be 'A' and 'V' years respectively.

=> A - 8 = 4/3 (V - 8) and A + 8 = 6/5 (V + 8)

=> 3/4(A - 8) = V - 8 and 5/6(A + 8) = V + 8

V = 3/4 (A - 8) + 8 = 5/6 (A + 8) - 8

=> 3/4 A - 6 + 8 = 5/6 A + 20/3 - 8

=> 10 - 20/3 = 10/12 A - 9/12 A

=> 10/3 = A/12 => A = 40.

1 59
Q:

Eighteen years ago, a mother was three times as old as her daughter. Now the mother is only twice as old as her daughter. Then the sum of the present ages of daughter and the mother is ?

 A) 84 yrs B) 96 yrs C) 116 yrs D) 108 yrs

Explanation:

Let the present ages of the mother and daughter be 2x and x years respectively.
Then, (2x - 18) = 3(x - 18) => x = 36
Required sum = (2x + x) = 108 years.

2 52
Q:

When Ram was born, his father was 32 years older than his brother and his mother was 25 years older than his sister. If Ram's brother is 6 years older than Ram and his mother is 3 years younger than his father, how old was Ram's sister when Ram was born ?

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

Explanation:

Ram age when he was born = 0 years
=> His brother's age = 6 year
=> His father's age = brother age + 32years = 6+32 = 38
=> His mother's age = father's age - 3 = 35
So sister's age = 35-25 = 10years.

1 110
Q:

If Reena’s age was twice of her present age, when subtracted from four times three years from hence, with three times the three years before her present age. What will be her age after one year ?

 A) 22 yrs B) 21 yrs C) 20 yrs D) 24 yrs