Answer:
35
Step-by-step explanation:
If S is the number of speed boats, C is the number of canoes, and Y is the number of yachts, then we can use the ratios and quantities provided in the problem statement to write a system of equations.
S / C = 6 / 7
S / Y = 6 / 9
Y = S + 15
Substitute the third equation into the second, then solve for S by cross-multiplying.
S / (S + 15) = 6 / 9
9S = 6(S + 15)
9S = 6S + 90
3S = 90
S = 30
There are 30 speed boats. Substitute into the first equation to find the number of canoes.
30 / C = 6 / 7
210 = 6C
C = 35
There are 35 canoes.
