4. Ramesh has enough money for 6 weeks if he spends Rs 1400 per week during summer vacation. How long will the money last if he spends Rs 1050 per week?

Solution( By Unitary Method) :

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

∵ By spending Rs 1400 per week the money lasts for 6 weeks.

∴ By spending Re 1 per week the money lasts for 6×1400 weeks. |
Explanation: For Re 1 per week spending the money will lasts for more numbers of weeks. . Therefore multiplication has been done. |

∴ By spending Re 1050 per week the money will last for (6×1400)/1050 weeks. |
Explanation:For Rs 1050 per week spending, the money will lasts for less numbers of weeks in comparison to previous spending of Re 1 per week. Therefore division has been done. |

= 8400/1050 = 8 weeks Ans. |