Question

bella saw that 7 out of 11 people brought an umbrella to the beach.There were 99 people there.how many of them did not have a beach umbrella

Answer 1

50 people did NOT bring an umbrella

Answer 2

So if 7 out of 11 people DID bring an umbrella, that means that 4 out of 11 people didn't. So cross  multiply! (:
4/11 = x/99
In order to get x, 99 times 11, then divide that by 6 to get 36. x=36.
So 36 people did not have a beach umbrella. 
xx