Venn diagram

[bhugra.ashish]

Source: NOVA maths

If in a certain school 20 students are taking math and 10 are taking history and 7 are taking both, how many students are taking either math or history?
(A) 20 (B) 22 (C) 23 (D) 25 (E) 29

Solution as per NOVA:
By the principle stated above, we add 10 and 20 and then subtract 7 from the result. Thus, there
are (10 + 20) - 7 = 23 students. The answer is (C).
.............................

Here, the question is how many take either maths or history.
The solution captures either maths / history or both.
Is my understanding correct ? Or are "EITHER MATHS OR HISTORY" and "EITHER MATHS OR HISTORY OR BOTH" same ??

Also, when you say either maths or history does it mean ONLY maths or ONLY history ??

[messi10]

I think it means either maths or history but NOT both

[karan13]

the solution given is for the total number of students by the formula total = group 1 +group 2- both.

The question is asking "how many students are taking either math or history". So that should translate to the total no of students in the class. Tricky language but i think is correct.

[jnelson0612]

Yes, the language is not ideal. It should say "either math or history but not both".