Dad is twice as old as Junior. Gramps is twice as old as Dad. The sum of the three ages is 140. How old is Gramps?​

80

Step-by-step explanation:

We can start of with Junior's age. Then if dad is twice as old as Junior, then we add 2 parts and get 3 parts. Then Gramps is twice as old as Dad so we add 4 parts and get 7 parts. Now we divided 140 by 7. We get 20. This is Junior's age. By looking at that, we know Dad is 40, and Gramps is 80.

Gramps is 80 years old.

Hi! I'm happy to help!

We can say that Junior is x years old. This would mean that Dad is 2x years old, and Gramps is 4x years old. All together, their age is 7x. We can write an equation to solve.

7x=140

Divide both sides by 7 to find out x.

x=20

This means that Junior is 20 years old. Dad is double that, so he is 40 years old. And Gramps is double that so he is 80 years old.

To check our answer we can add all of them together.

20+40+80

140

This means that Gramps is 80 years old.

I hope this was helpful, keep learning! :D