Correct Answer - Option 3 : 81
Given:
The number of songs on which Y danced = 16 more than the average of the number of songs on which X and Z
The ratio of number of songs on which X and Y danced = 27 ∶ 32
The number of songs on which Z danced = 79
Formula:
If the ratio of A and B is a ∶ b, assume A = ak and B = bk where k is a constant.
Calculation:
Let number of songs on which X and Y danced be 27x and 32x
The number of songs on which Y danced = 16 more than the average of the number of songs on which X and Z
⇒ 32x = 16 + (27x + 79)/2
⇒ 64x – 27x = 32 + 79
⇒ 37x = 111
⇒ x = 3
The number of songs on which X danced = 27x
⇒ 27 × 3 = 81
∴ The number of songs on which X danced is 81.