Let Tom = x
Then Shane is x +17 ( 17 more than Tom)
Sophie = 2x ( twice Tom's score)
Now you have:
X +(x+17) + 2x = 161
Simplify:
4x +17 = 161
Subtract 17 from both sides:
4x = 144
Divide both sides by 4:
x = 144 / 4
x = 36
Shane = x +17 = 36 +17 = 53