SOLUTION: Aby and his brother Ben are teenagers. Ben is 3 years younger than Aby and the GCF of their age is 3. how old is Ben?

Question 936903: Aby and his brother Ben are teenagers. Ben is 3 years younger than Aby and the GCF of their age is 3. how old is Ben?
Answer by Edwin McCravy(20056) (Show Source): You can put this solution on YOUR website!
Aby and his brother Ben are teenagers.

13 ≤ A ≤ 19,   13 ≤ B ≤ 19

Ben is 3 years younger than Aby

B = A-3, so we substitute A-3 for B and

13 ≤ B ≤ 19 becomes

13 ≤ A-3 ≤ 19

We add 3 to all three sides:

16 ≤ A ≤ 22, but since A ≤ 19,

16 ≤ A ≤ 19

the GCF of their age is 3

So A is a multiple of 3 and the only multiple of 3
between 16 and 19 is 18, so 

A = 18 and B = A-3 = 18-3 = 15.

Edwin

RELATED QUESTIONS
Abby and his brother Ben are teenagers. Ben is 3 years younger than Abby and the GCF of... (answered by CubeyThePenguin)

Zach is 15 years old. This is 3 years younger than Ben. How old is Ben (answered by TimothyLamb)

Rey is half as old as his cousin Ben and 3 years younger than his sister Susan. In 5... (answered by fractalier)

Tony is 3 times as old as Ben and is also 16 years older than Ben . How old is Ben... (answered by Alan3354)

Ben is 3 years older than his sisyer and a third of the age of his mother.His father is 4 (answered by jorel1380)

Ben is 12 years older than Sally. The sum of their age is 50. How old is Ben... (answered by Alan3354)

Bill and Ben are twins. Bill is 3 years older than Ben, how is this... (answered by JulietG)

Sam is 15 years younger than his friend Ben. The total of their ages is 55 years. a.How... (answered by josgarithmetic,ikleyn)

Ari is 3 times as old as Ben now. In 6 years' time, the total age of Ari and Ben will be... (answered by josgarithmetic,greenestamps)