The ratio of the ages of A, B and C, 5 years ago, was 4 : 5 : 7. The sum of their present ages is 135 years. What will be the sum of the ages (in years) of B and C, 3 years from now?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 106.
The ratio of the ages of A, B and C, 5 years ago, was 4 : 5 : 7.
The sum of their present ages is 135 years.
Total = Average × Number of entities
Let the common ratio be Q.
So, 5 years ago, the ages of A, B, and C are 4Q, 5Q, and 7Q respectively.
Now, their present ages are (4Q + 5), (5Q + 5), and (7Q + 5) respectively.
According to the question -
(4Q + 5) + (5Q + 5) + (7Q + 5) = 135
16Q + 15 = 135
16Q = 135 - 15
16Q = 120
Q = 7.5
The present age of B = (5 × 7.5 + 5) = 42.5 years
The present age of C = (7 × 7.5 + 5) = 57.5 years
Now, the sum of the ages of B and C, 3 years from now = (42.5 + 3) + (57.5 + 3) = 106 years