For these problems you have to use PEMDAS so for problem 15 you would do the parentheses first, (21-3) you get 18 and then exponents, 3^2, you get 9, no multiplication but there is division so take your answers, 18 and 9 and divide them, you get 2, so the answer to 15 is 2.
Answer:
The number of fishing boats in the bay = 64.
Step-by-step explanation:
The total number of sailboats = 24
Let us assume the number if fishing boats in the bay = m
⇒ Ratio of fishing boats to sailboats in a bay = m : 24.
Now, the ratio of fishing boats to sailboats in a bay is 8 : 3.
So, by the RATIO OF PROPORTION:

⇒ m = 64
Hence the number of fishing boats in the bay = 64.
Step-by-step explanation:
only 10 and 12. luck to you