Question 950355
Let's call Jack "a" and Jill "b".

The problem says that a (Jack) is 2 times b (Jill). Write this in equation form:

2b + b = 78 
3b = 78 Divide both sides by 3
b = 26 Great! Jill is 26, and Jack is 26*2 = 52
Proof: 26 + 52 = 78