You buy a shirt that is on sale for 30% off. You pay $22.40. Your friend wants to know the original price of the shirt. Whats the answer?

30% off

theh shirt is 22.40 after discount

original=100%

original-discount=22.40

100-30=70%

22.40=70%

percent means parts out of 100

22.40=70/100 of original

multiply both sides by 100/70 to clear fraction

2240/70=original

32=original

original=$32.00

The price of the shirt is $22.40.

Since it is 30% off, you would need to add back on the 30%

22.40*100% is 22.40, So you would do 22.40*130% to bring back the thirty.

The answer is $29.12

To check the answer, you can do 29.12*70% because 100-30=70