JAMB - Mathematics (2012 - No. 9)
In a class of 46 students, 22 play football and 26 play volleyball. If 3 students play both games, how many play neither?
1
2
3
4
Giải thích
n(f \(\cap\) v) + n(f) + n(v) + n(f \(\cap\) v) = 46
3 + 19 + 23 + x = 46
22 + 23 + x = 46
45 + x = 46
x = 46 - 45
x = 1
3 + 19 + 23 + x = 46
22 + 23 + x = 46
45 + x = 46
x = 46 - 45
x = 1