SOLUTION: I have 3 cousins on my dad's side. The product of their ages is 84. Next year the youngest will be 1/4 the age of the middle cousin. In 2 years from now, the oldest will be twice t

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: I have 3 cousins on my dad's side. The product of their ages is 84. Next year the youngest will be 1/4 the age of the middle cousin. In 2 years from now, the oldest will be twice t      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 695938: I have 3 cousins on my dad's side. The product of their ages is 84. Next year the youngest will be 1/4 the age of the middle cousin. In 2 years from now, the oldest will be twice the current age of the middle. What is the age of my oldest cousin?


Can you please explain how you got the answer please. I'm in 4th grade and I want to learn how to solve it.
Thank you.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
I have 3 cousins on my dad's side. The product of their ages is 84.
Next year the youngest will be 1/4 the age of the middle cousin.
In 2 years from now, the oldest will be twice the current age of the middle.
What is the age of my oldest cousin?
:
Let the cousins' ages be a, b, c; a is the oldest
:
Write an equation for each statement
:
"The product of their ages is 84."
a * b * c = 84
:
" Next year the youngest will be 1/4 the age of the middle cousin."
c + 1 = 1%2F4(b+1)
From this we know b + 1 is a multiple of 4, (we only have integers here)
And it has to be a factor of 84
b = 3, does not work try: b = 7
c + 1 = 1%2F4(7+1)
c + 1 = 1%2F48
c + 1 = 2
c = 2 - 1
c = 1
:
" In 2 years from now, the oldest will be twice the current age of the middle."
a + 2 = 2b
a + 2 = 2(7)
a = 14 - 2
a = 12
:
We have a = 12, b = 7, c = 1
12 * 7 * 1 = 84
:
What is the age of my oldest cousin? 12 yrs old
:
:
That's pretty hard for 4th grade!!