For question 11 the answer is 6 because both shapes are similar one is larger than the other so we take the scale which will be 1/4 then multiply 24 by 1/4 = 6
For question 12 the answer is 4 because both shapes are similar one is larger than the other so we take the scale which will be 1/2 then multiply 8 by 1/2 = 4
Hope you got it and u may revise similarity and enlargement scales for a clearer concept