Question

Justin and David were comparing text messages. For every 8 messages Justin sent, David sent 12 messages. Together Justin and David have sent 450 messages last month. How many messages did each person send?

Answer 1

The number of messages sent by Justin was
`180\ messages`

The number of messages sent by David was
`270\ messages`

Explanation:

Let

x-----> number of messages sent by Justin

y----> number of messages sent by David

we know that

`(x)/(y)=(8)/(12)`

`x=(8)/(12)y` ----> equation A

`x+y=450` -----> equation B

substitute equation A in equation B and solve for y

`(8)/(12)y+y=450`

`(20)/(12)y=450`

`y=450*12/20=270\ messages`

Find the value of x

`x=(8)/(12)(270)=180\ messages`

therefore

The number of messages sent by Justin was
`180\ messages`

The number of messages sent by David was
`270\ messages`