Answer:

10

Step-by-step explanation:

we can solve for how many boy scouts are there in the class by either doing this:

(50 * 80) / 100 = 4000/100 = 40

or this:

50 * 80% = 50 * 0.8 = 40

either way we get 40 pupils who are scouters, to find th amount who are not scouters we simply do 50 - 40.

Which we get 10.

Final Answer: There are 10 pupils who are not scouters.