Need help in forming equations for these two apparently simple scenarios!

No. 1

Three eights of the class got sick. Three more students got sick, leaving only half the class at school. How many students were not sick?

(possible choice of answer: 8, 12, 16, 20)

No. 2

3/4 of a jar of lollies are multi-coloured and the rest are black. 6 of the black lollies are eaten and now there is 6/7 of the jar of multicoloured lollies. How many black lollies were in the jar at the start?

(possible answers: 6, 8, 10, 12)