Word Problem

Mar 2019
196
1
TTF area
This is the question attached. How do I set this up to start solving?
Screenshot 2020-03-16 at 8.24.33 AM.png
 

romsek

Math Team
Sep 2015
2,961
1,674
USA
you have 3 unknown long distance rates to solve for $a, b, c$ (australia, britain, china), dollars per minute.

those rates times the minutes spent on calls to those places equals the total charges for each month

so for example for september

$90a+130b+180c=15.00$

you can figure out the rest
 
Mar 2019
196
1
TTF area
you have 3 unknown long distance rates to solve for $a, b, c$ (australia, britain, china), dollars per minute.

those rates times the minutes spent on calls to those places equals the total charges for each month

so for example for september

$90a+130b+180c=15.00$

you can figure out the rest
So 70a+ 100b+120c=11.00 and 50a+110b+150c=12.10

solving this gives me a c=0.03,b=0.06,a=0.02