Quote:

75 pupils: 48 pupils like ready salted, 35 like cheese & onion.

i) If 7 pupils do not like either flavor, how many like both?

. . . Answer: 15

iia) What is the greatest possible number of pupils who could like both?

. . . Answer: 35

iib) What is the smallest possible number of pupils who could like both?

. . . Answer: 8

All correct . . . Good work!

Now this is the part that i cannot figure out:

The number of pupils who like both is twice the number who do not like either;

iii) What fraction of the pupils who like ready salted do not like cheese & onion?