Answer:
98
Step-by-step explanation:
Let the sailboats be s and the dinghies be d.
We have that:
s : d = 5 : 7
In other words:
s / d = 5 / 7
If there are 70 sailboats, this implies that s = 70
=> 70 / d = 5 / 7
=> d = (70 * 7) / 5 = 490 / 5 = 98
There will be 98 dinghies.
