
Hi,
Can someone help to explain this qns?
Thanks
Hi,
Can someone help to explain this qns?
Thanks
Average price of 14 books -> u
Total price of 14 books -> 14u
Average price of 12 books -> u + $2.55
Total price of 12 books -> 12(u + 2.55) = 12u + 30.6
14u = (12u + 30.6) + (26.50 × 2)
2u = 83.6
u = 41.8
Average of books after adding 2 books at $26.50 each -> $41.80
Thank you 😊
While the problem can be solved by formulating equations as I had done in the first solution, I think it would be good for the child to understand the concept of averages.
When the average decreased by $2.55 after adding 2 new books, the 12 original books “lost” $2.55 in value.
These amounts were “added” to the prices of the 2 new books, so that their prices appeared to be same as the other 12.
So, the new average is simply $26.50 + (6 × $2.55) = $41.80
While the problem can be solved by formulating equations as I had done in the first solution, I think it would be good for the child to understand the concept of averages.
When the average decreased by $2.55 after adding 2 new books, the 12 original books “lost” $2.55 in value.
These amounts were “added” to the prices of the 2 new books, so that their prices appeared to be same as the other 12.
So, the new average is simply $26.50 + (6 × $2.55) = $41.80