Question

The sum of the ages of Noah and Billy is 25; the sum of the ages of Noah and Ty is 20; and the sum of the ages of Billy and Ty is 31. Who is the oldest of the three and how old is he?

Answer 1

the oldest is Ty and his age is 24

Explanation:

Let us assume the billy age be x

Noah age be y

And, Ty age be z

Now according to the question

y + x = 25 ..........(1)

y + z = 20..........(2)

x + z = 31..............(3)

z = 31 - x

since

y + z = 20

y + 31 - x = 20

y - x = -11 .............(4)

Now solve (1) and (4) equation

So,

y + x = 25

y - x = -11

2y = 36

y = 18

x = 25 - 18

= 7

z = 31-7

= 24

Hence, the oldest is Ty and his age is 24