An orphanage had provision of food for 300 boys for 90 days. After 20 days, 50 boys left the orphanage. The number of days for which remaining food will last is : Choose the correct option.
A) 70  B) 72  C) 80  D) 84  E) 86
Explanation :   Solution: After 20 days : 300 boys had food for 70 days.   Suppose 250 boys had food for x days. Now, less boys, more days (Indirect proportion)   .'. 250 : 300 : : 70 : x   =&gt; 250*x = 300*70   =&gt; x = 300*70/250= 
<gadget id="calculator">300*70/250</gadget>
<output>84</output>
84.   Answer : 84
<result>D</result>
An orphanage had provision of food for 300 boys for 90 days. After 20 days, 50 boys left the orphanage. The number of days for which remaining food will last is :