In a mathematics test, Shane scored 17 marks more than Tom while Sophie 's score is twice of Tom 's score. If their total is 161, what is Shane ' s score?

(linear equations)

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