Notebooks of a class were corrected with ink pen while 22 notebooks were corrected with colour pencil. If 4 notebooks were corrected with both, what is the strength of class?
30
32
28
25
B.
32
Notebooks were corrected with ink pen =14
Notebooks were corrected with colour pencil = 22
Notebooks were corrected with both = 4
Therefore total strength of class = 14 + 22 - 4
= 32
