A student gets 50% in one subject, 70% in the other. To get an overall of 70% how much should get in third subject.  Select:  A) 90%  B) 25%  C) 45%  D) 55%  E) 65%
Let the 3rd subject % = x   50+70+x = 3*70   120+x =210   x = 210-120= 
<gadget id="calculator">210-120</gadget>
<output>90</output>
90   90%nswer : 90%
<result>A</result>
A student gets 50% in one subject, 70% in the other. To get an overall of 70% how much should get in third subject.