Question

500 soldiers in a fort had enough food for 30 days . after 6 days, some soldiers were sent to another fort and thus the food lasted for 32 more days . how many soldiers left the fort ?

Answer 1

500 soldiers x 30 days
=  15000 food supplies

500 soldiers x 6 days=3000 food supplies
 
15000 food supply - 3000 food supply
=12000 food supply will last for 32 days
 
12000 food supply/ 32days =375 soldiers 
500 soldiers- 375 soldiers= 125 soldiers

Answer 2

There is enough food for 500 soldiers for 30 days. Say that each soldier has one unit of food a day. So there are 500 units for one day and 500 × 30 = 15000 units for the 30 days. So as per the question after 6 days some soldiers left the fort, it means 500 × 6 = 3000 units are consumed by the time some soldiers left. Total unit left = 15000 - 3000 = 12000 units. Now we know that x units are consumed a day, and the food lasted for 32 days more. so the following formula is used to solve this problem.
Number of soldiers left × Days of food will last = Unit of left
x × 32 = 12000
x = 12000 ÷ 32
x = 375 
375 soldiers left in the fort.
500 - 375 = 125 soldiers had left the fort.