Question

1000 Soliders in a fort had enough food for 20 days. But some soldiers were transferred to another fort and the food lasted for 25 days. How many soldiers were transferred? ​

Answer 1

Let the number of soldiers transferred be = x

by unitary method

number of soldiers      ║   days food lasted

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 1000                           ║         20

1000-x                         ║          25

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 by inverse variation  

1000 × 20 = (1000-x) × 25

1000 ×20/ 25 =1000 - x

800 = 1000 -x

x= 1000 - 800

 = 200

∴200 soldiers were transferred to another fort.