60% of the total donation required by the school was collected when 50% of the parents donated an average of Rs 1200. Find the average amount that should be donated by the rest of 50% of parents so that the school has the whole amount that was required.

60% of the total donation required by the school was collected when 50% of the parents donated an average of Rs 1200. Find the average amount that should be donated by the rest of 50% of parents so that the school has the whole amount that was required. Correct Answer Rs. 800

Given:

50% of the parents donated an average of Rs. 1200

60% of the total donation = Donation of 50% of the parents

Formula used:

Total = Average × Number of observations

Calculation:

Let total parents be 100, and total donation be Rs. x

50% of total parents = 50% of 100 = 50

Total amount paid by 50 parents = 1200 × 50 = 60000

60% of the total donation = 60000

⇒ 60% of x = 60000

⇒ x = 100000

Remaining amount = Total amount – 60000

⇒ Remaining amount = 100000 – 60000 = 40000

This amount is to be paid by 50 parents

The average amount to be paid by the rest of the parents (i.e. 50) = 40000/50 = Rs. 800

∴ The average amount to be paid by the rest of the parents is Rs. 800