Answer:
11%
Explanation:
Shaun's percentage of winning against Mike is 8/11 or 73%
Shaun's percentage of winning against Tim is 7/12 or 58%
Shaun's percentage of losing against Mike is 100-73 = 27%
Shaun's percentage of losing against Tim is 100-58 = 42%
Shaun's percentage of losing against Mike and Tim is .27 x .42 which is approximately 11%