There are 20 maths problems in the each.For each right answer,you get 0.For each wrong answer,you lo

题目

There are 20 maths problems in the each.For each right answer,you get 0.For each wrong answer,you lose 2 points instead of getting points (倒扣2分）.If Lucy gets a mark (分数）,which is a prime mumber(质数）,the largest number of maths problems she works out(解出）is ____.
A.13 B.15 C.16 D.17
第一句each改为test sorry,我打错了 应该是For each right answer,you get 5,不答得0,答错得-2 ok.

答案

C.16