Correct Answer - Option 2 : 400
Given:
The ratio of red and blue balls is 8 ∶ 11
The number of blue balls is 550
Calculation:
Let the number of red balls be 8x,
Then the number of blue will be 11x,
According to the question,
⇒ 11x = 550
⇒ x = 550/11
⇒ x = 50
Number of the red balls,
⇒ 8x = 8 × 50
⇒ 400
∴ The number of red balls is 400