Question

In a class of 800. student are obligated to pass all three subjects to move to the next class. if 699 passed all three,80 failled chm, 20 failed maths and 30 failed phy, 28 failed chm and phy, 16 failed chm and maths and 10 failed maths and phy.if student who failed more than one subject are not allowed to move to the next class, how many student will move to the next class?.

Answer 1

if x students failed all three, then
80+20+20-(28+16+10) + x = 800-699
x = 35
28+16+10-35 = 19 failed exactly one subject
so, 699+19 = 718 move to the next class