
By: ricebowl1912 (offline) Saturday, August 28 2010 @ 01:02 AM CDT (Read 13328 times)



ricebowl1912 
Need help on the following 2 problem sum questions (pls provide workings) :
1) A cupboard has 3 shelves. There are 48 books altogether on the shelves. Mei Lin removed 8 books from the top shelf and placed them on the middle shelf. She removed 6 books from the middle shelf and placed them on the lowest shelf. As a result, 3 shelves had the same number of books. How many books were on the middle shelf at first?
2) Tom and Peter shared a sum of money. If Tom gave $350 to Peter, they would have the same amount of money. If Peter gave $100 to Tom, he would have half as much money as Tom. How much money did Tom had at first?

Newbie
Registered: 07/28/10 Posts: 5





By: tanhuimin (online) Sunday, August 29 2010 @ 05:24 AM CDT



tanhuimin 
1) A cupboard has 3 shelves. There are 48 books altogether on the shelves. Mei Lin removed 8 books from the top shelf and placed them on the middle shelf. She removed 6 books from the middle shelf and placed them on the lowest shelf. As a result, 3 shelves had the same number of books. How many books were on the middle shelf at first?
Solution :
Top Shelf 8
Middle Shelf +8 6
Lowest Shelf +6
48/3 = 16
middle shelf +8 6 = 16
middle shelf = 16 2 = 14
Answer : 14 books were on the middle shelf at first.
2) Tom and Peter shared a sum of money. If Tom gave $350 to Peter, they would have the same amount of money. If Peter gave $100 to Tom, he would have half as much money as Tom. How much money did Tom had at first?
Tom gave $350 to Peter, and they would have the same amount of money implies that Tom has $700 mode than Peter
use this as a base to draw a model.
From the model, (see attached)
1u = 100 + 700 + 100 = 900
Tom has 2 x 900  100 = 1700.
Answer : Tm has $1700 at first.

Junior
Registered: 12/31/06 Posts: 18





By: ricebowl1912 (offline) Friday, September 03 2010 @ 08:06 AM CDT



ricebowl1912 
Your workings really help! Thanks!

Newbie
Registered: 07/28/10 Posts: 5





By: rathanackumr (offline) Sunday, September 05 2010 @ 08:51 PM CDT



rathanackumr 
Model method attached. Cheers!

Junior
Registered: 07/22/10 Posts: 18





By: rathanackumr (offline) Sunday, September 05 2010 @ 10:33 PM CDT



rathanackumr 
Model method for 2nd question attached. cheers!

Junior
Registered: 07/22/10 Posts: 18



