One day a store sold 30 sweatshirts. White ones cost $11.95 and yellow ones cost$11.50. In all, $349.95 worth of sweatshirts were sold. How many of each color were sold?

With this, I would use a guess and check method.

Start by splitting them half.

$11.95x15 sweatshirts = $179.25

$11.50x15 sweatshirts = $172.50

Then you add the totals to see how close you are.

$197.25+$172.50=$351.75

That's a little high. so we'll shift the amount of sweatshirts.

$11.95x14 sweatshirts = $167.30

$11.50x16 sweatshirts = $184.00

And add the totals again.

$167.30+184.00 = $351.30

Closer, but too high still, so we'll shift it more in the direction we're going.

$11.95x11 sweatshirts = $131.45

$11.50x 19 sweatshirts = $218.50

Once again, add the totals to check if it matches.

$131.45+$218.50 = $349.95

Therefore, 11 white sweatshirts and 19 yellow sweatshirts were sold.