If 35 people play hockey and 10 people play both football and hockey and if 10 people play hockey and cricket and 5 people play all three games then the number of people playing hockey alone is? Select.
A) 10
B) 15
C) 20
D) 25
E) 30
hockey =35 (given)   hockey , cricket , football = 5(given)   hockey , cricket = 10(given)   hockey , football = 10(given)   only hockey = 35 - 5(h,c,f)-5(h,c (10-5)) -5(h,f(10-5))=35-5-5-5= 
<gadget id="calculator">35-5-5-5</gadget>
<output>20</output>
20   ANSWER:20
<result>C</result>
If 35 people play hockey and 10 people play both football and hockey and if 10 people play hockey and cricket and 5 people play all three games then the number of people playing hockey alone is?