word problems

Question

Jack is twice as old as lacy. In 3 three years the sum of their age will be 54. how old are they now

Answer 1

A quick way to answer this question is to work backward.

 

 

Let's take a similar question with different values for an example.  

 

"Jack is twice as old as Jill. In five years the sum of their age will be 59. how old are they now."

 

Subtract 5 from 59 to get the current combined age of 54. Then, divide 54 by 3 to get Jill's age of 18.  Multiply 18 by 2 to get Jack's age of 36.

So, in this new problem:

Jill is 18
Jack is 36.

 

To check our work, their current combined age (18+36) is 54 so in five years (54+5) they will be 59.