Passed Both Maths & French: 42 Students

[John O' Meara]

In an examination 86 students out of 108 pass mathematics, 35 passed
French and 3 failed both subjects. How many passed in both? Thanks guys.

 

[nocturnal]

What are your ideas so far? Have you heard of the principle of inclusion-exclusion?

 

[Hurkyl]

There are 4 cases. Look at the 4 cases.

 

[Mathyards]

Draw a Venn diagram ;assume those who passed both to be x ;you should get x = 16.