In a class of 60 students, 20 did not opt for math. 15 did not opt for science and 5 did not opt for either. How many students of the class opted for both math and science?  Choose the correct choice from the following answers
A) 23  B) 25  C) 27  D) 30  E) 48
60 students total   20 did not opt for math   15 did not opt for science   5 did not opt for either   Total of 40 students in math and 10 did not opt for sci but did for math    40-10= 
<gadget id="calculator"> 40-10</gadget>
<output>30</output>
30   30 students of the class opted for both math and science   Answer:   D. 30
<result>D</result>
In a class of 60 students, 20 did not opt for math. 15 did not opt for science and 5 did not opt for either. How many students of the class opted for both math and science?