问题

wretdgdh

All trainees in a certain aviator training program must take both a written test and a flight test. If 70 percent of the trainees passed the written test, and 80 percent of the trainees passed the flight test, what percent of the trainees passed both tests?

(1) 10 percent of the trainees did not pass either test.

(2) 20 percent of the trainees passed only the flight test.

这题不会做555...大家能告诉我详细的解题思路么?

himba

10%没有通过任何一个测试.90%至少通过一项测试. so两项都通过的为(70%+80%-90%)=60%.条件1充分. 条件2为 80%-20%=60%条件2充分.