Ok the answer of 6 are 12, 18, 24, 30, 36, 42, and 48. The multiples of 9 are 18,27,36,45,54,63,72,81,90,99,108,117,126,135,144,153,162,171,180,189,198,. Hope it helps!
Hmm, 3 shirts cost $84 all together 84 divided by 3 is 28. 28+28+28=84. Each shirt had to be $28 to equal $84 for the final price. Hope this was right!