Correct Answer - Option 2 : 7 : 15
Given:
The ratio of A and B is 7 : 9
If A is increased by 50 and B is increased by 22 the ratio becomes 8 : 5
Calculations:
Let the value of A and B be 7y and 9y respectively.
If the value of A is increased by 50 then, we get
⇒ 7y + 50
If the value of B is increased by 22 then, we get
⇒ 9y + 22
According to question, we have
⇒ (7y + 50)/(9y + 22) = 8/5
⇒ 5(7y + 50) = 8(9y + 22)
⇒ 35y + 250 = 72y + 176
⇒ 72y – 35y = 250 – 176
⇒ 37y = 74
⇒ y = 2
Thus, the value of A is 7y
⇒ 7 × 2 = 14
The value of B is 9y
⇒ 9 × 2 = 18
So, the value of 3A is 42
The value of 5B is 90
The ratio of 3A : 5B is
⇒ 42 : 90
⇒ 7 : 15
∴ The ratio of 3A : 5B is 7 : 15
