Two numbers are in the ratio 3 ∶ 5. If 10 is added with both the numbers, the ratio becomes 5 ∶ 7. What is the sum of two numbers?
- AOption (a)
35
- BOption (b)
40
- COption (c)
8
- DOption (d)
16
View answer & explanationHide answer & explanation
Correct answer
40
Why this answer is correct
Given:
Initial ratio of the two numbers = 3 ∶ 5
When 10 is added to both numbers, the ratio becomes 5 ∶ 7.
Formula Used:
Ratio equation: \(\frac{a+10}{b+10} = \frac{5}{7}\)
Calculation:
Let the numbers be 3x and 5x.
According to the problem:
\(\frac{3x + 10}{5x + 10} = \frac{5}{7}\)
Cross-multiplying gives:
⇒ 7(3x + 10) = 5(5x + 10)
⇒ 21x + 70 = 25x + 50
⇒ 21x - 25x = 50 - 70
⇒ -4x = -20
⇒ x = 5
The two numbers are:
First number = 3x = 3 × 5 = 15
Second number = 5x = 5 × 5 = 25
Sum of the two numbers = 15 + 25 = 40
The sum of the two numbers is 40.




