3. Eight people eat a stock of food in 30 days. How many people will consume the stock of food in 20 days?

Solution( By Unitary Method) :

Here we have to find out nos. of people. Therefore we will keep the people at right side in the statement.

∵ In 30 days a stock of food is eaten by 8 people.

∴ In 1 day same stock of food will be eaten by 30×8 people. |
Explanation: For 1 day more nos. of people will be needed to eat the same stock of food. Therefore multiplication has been done. |

∴ In 20 days same stock of food will be eaten by (30×8)/20 people. |
Explanation: For 20 days lesser nos. of people will be needed to eat the same stock of food. Therefore division has been done.,/p> |

= 240/20 = 12 people Ans. |