Question

If a * b = ab + b - a, what is the value of c such that c * (2 * 5) = 97?
1. 8
2. 7
3. 3
4. 91

Answer 1

Correct Answer - Option 2 : 7

Given:

If a * b = ab + b - a

Calculation:

If a * b = ab + b - a

Follow this method 

c * (2 * 5) = 97

⇒ c * (2 × 5 + 5 - 2) = 97

⇒ c * (10 + 5 - 2) = 97

⇒ c * 13 = 97

Again follow 

⇒ c × 13 + 13 - c = 97

⇒ 12 c = 84

⇒ c = 7

∴ The value of c is 7.