Hello!
7 out of 11 people brought an umbrella to the beach
this is a fraction of 7/11
We multiply this by 99 to get how many people brought an umbrella out of 99
7/11 * 99 = 63
You subtract this from 99 to see how many did not have an umbrella
99 - 63 = 36
The answer is 36 people
Hope this helps!