The student council sold 661 T-shirts, some at $10 and some at $12. When recording the amount of T-shirts they had sold at each of the two prices, they reversed the amounts. They thought they made $378 more than they really did. How many T-shirts actually were sold at $10 per shirt?

Guest May 22, 2020

#1**0 **

Well, since x = 10 dollar shirts

Then:

661 - x = 12 dollar shirts

10x + 12 (661-x) + 378 = 12x + 10(661-x)

10x +7932 - 12x + 378 = 12x +6610 -10x

So: x = 425 shirts at $10

Hope this helps, whymenotsmart^m^.

whymenotsmart May 22, 2020

#2**+2 **

So let's say x is the money they made at 10 dollars(a) and 12(b). The two variables are for the number sold.

They reversed it so that it was 12(a) and 10(b).

Thus

12a +10b = 10a + 12b + 378

Some rearrangement:

12a +10b - 10a -12 b = 378

2a - 2b = 378

a-b = 189

So we sold 661 tshirts.

661-189= 472,/2 = 236

So b = 236 and a = 236 + 189 = 425.

425*10 + 236*12 = 7082

Flip around, 425* 12 + 236 * 10 = 7460.

7460- 7082 = 278.

Thus 425 at 10, 236 at 12.

if you don't understand anything feel free to ask.

Great solution, whymeissmart hehehe

hugomimihu May 22, 2020

#3**0 **

thanks, you too, maybe I should change my name, so you would stop making fun of me (JK....)!!

whymenotsmart May 22, 2020

#4**+1 **

I actually don't think that's possible...

Whymenottnewton

LOL

I can do this all day!

hugomimihu
May 22, 2020

#5**0 **

LOL, for some reason, titaniumrome is in the leaderboard now, for some reason, but then I scroll down for leaderboards rom is in the leaderboards, you know what I mean, hugo??

whymenotsmart May 22, 2020