Because 51.00 divided by 2 equals 25.5 (which is the cost for a tie), and 25.5 times 3 equals 76.5. Then 88.50- 76.50 = 12, and 12/2 equals 6 which is the cost for each hat.
You can use soh cah toa. Basically you pic one side and if the interior angle is opposite or next to it, you you soh, or cah, or toa, it's based on where the angle is.
6 (Allison's number of blue) divided by 16 (Allison's total) is equal to x (Sadie's blue) out of 24 (Sadie's total). So 6/16=3/8=x/24. So x=3*3, so Sadie's amount of blue pencils is 9. The rest of Sadie's pencils are yellow, so Sadie has 24-9=15 yellow pencils.
