Two numbers are respectively 40% and 60% more than the third number. The ratio of the first two numbers when the first number is increased by 4 becomes 9 ∶ 8. Find the ratio of the first two numbers when the second number is increased by 5.
Two numbers are respectively 40% and 60% more than the third number. The ratio of the first two numbers when the first number is increased by 4 becomes 9 ∶ 8. Find the ratio of the first two numbers when the second number is increased by 5. Correct Answer 2 ∶ 3
Given:
Two numbers are respectively 40% and 60% more than the third number.
The ratio of the two numbers when the first is increased by 4 becomes 9 : 8.
Formula:
If the ratio of A and B is a ∶ b, assume A = ak and B = bk
where k is a constant.
Calculation:
Let the third number be x.
First number = (140/100) of x = 7x/5
Second number = (160/100) of x = 8x/5
According to the question
Ratio = ((7x/5) + 4))/(8x/5) = 9/8
⇒ (7x + 20)/(8x) = 9/8
⇒ 2x = 20
⇒ x = 10
First number = 7x/5 = 14
Second number = 8x/5 = 16
The ratio of the two numbers when the second number is increased by 5
⇒ (14)/(16 + 5)
⇒ 14/21 = 2/3
∴ The ratio of the two numbers when the second number is increased by 5 is 2 ∶ 3