John scored twice the marks of Tom. The sum of their marks in the exam is 60. Then find how many marks Tom and John scored respectively. 

Let the score of Tom = x 

John scored twice the marks of Tom = 2x 

Sum of their marks = 60 

From above conditions we get x + 2x = 60; 

3x = 60

x = $\frac{60}{3}$

x = 20.

So, Tom scored x = 20

John scored 2x = 2(20) = 40.