A 12-oz cup of regular coffee at Starbucks has 13 times the amount of caffeine found in the same sized serving of decaffeinated coffee. Together they contain 280 mg of caffeine. How much caffeine is in each type of coffee? Keep trying to figure this out but I keep getting it wrong....

Question

A 12-oz cup of regular coffee at Starbucks has 13 times the amount of caffeine found in the same sized serving of decaffeinated coffee. Together they contain 280 mg of caffeine. How much caffeine is in each type of coffee?  Keep trying to figure this out but I keep getting it wrong....

anonymous · Answer

x is reg y is decaf
x+y=280
13y=x
13y+y=280
14y=280
y=20
x=260
check 20*13=260

anonymous · Answer

make sense?

anonymous · Answer

oh okay I see what I did wrong. Thanks!

anonymous · Answer

No problem:D