A school having four classes only have student strength of 10, 20, 30 and 40 respectively. The pass percentages of these classes are 80%, 30%, 60% and 90% respectively. What is the pass percentage for the entire school? Select the correct option:
A) 56%
B) 76%
C) 34%
D) 68%
E) 46%
80% of 10+30% of 20+60% of 30+90% of 40   =8+6+18+36= 
<gadget id="calculator">8+6+18+36</gadget>
<output>68</output>
now 68 of 100= 68%   ANSWER:68%
<result>D</result>
A school having four classes only have student strength of 10, 20, 30 and 40 respectively. The pass percentages of these classes are 80%, 30%, 60% and 90% respectively. What is the pass percentage for the entire school?