
By: veronica2566 (offline) Saturday, October 01 2011 @ 03:11 AM CDT (Read 1155 times)



veronica2566 
I need help in the following :
1) A rectangular tank, 50cm long, 42cm wide and 2/5 filled with water. When 8.4 litres of water was poured in, the height of the water rose by 25%. What was the height of the tank?
2) Sofian had 4 times as much money as Roy. After Sofian spent $9 and gave Roy $12, the 2 boys found that they had the same amount of money. How much did Roy have at first?
3) Fatin and Poly had a total of 72 cards,. Fatin gave 1/3 of her cards to Poly. Poly then gave 2/5 of the total cards she had back to Fatin. In the end, each of them had an equal number of cards. How many cards did Fatin have at first?
4) Dave completed a jigsaw puzzle in 7 days. For the first 3 days, he completed 2/7 of the puzzle. What fraction of the puzzle did he complete on each of the remaining days if he worked at a constant rate?
Appreciate very much!
Thanks!!!

Junior
Registered: 06/23/10 Posts: 24





By: ashlene (offline) Sunday, October 02 2011 @ 06:32 AM CDT



ashlene 
if im not wrong....
this is what i worked out...
Qn 2
3units=12+12+9=33
1unit = 11 (answer)
Qn 3
72 divide by 2 = 36
36 divide by 3 = 12
12 x 5=60
72  60 = 12
12 divide by 2 = 6
6 x 3 =18 (answer)
Qn 4
7/7  2/7 = 5/7
5/7 divided by 4 = 5/28 (answer)

Newbie
Registered: 09/20/10 Posts: 2





By: veronica2566 (offline) Sunday, October 02 2011 @ 06:47 PM CDT



veronica2566 

Junior
Registered: 06/23/10 Posts: 24





By: echeewh (offline) Monday, October 03 2011 @ 06:53 PM CDT



echeewh 
Hi Veronica,
This is the worked solution to your Qn 1.
Area of tank = 50 × 42 = 2100 cm2
Increase in height of water after 8.4 litres of water was poured in = (8.4 x 1000) / 2100 = 4 cm
So, 25% ? 4 cm
Original height of water = 100% ? 16 cm
Hence, 2/5 total ? 16 cm
5/5 total ? 16 × (5/2) = 40 cm
Ans: Height of tank was 40 cm
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 623





By: veronica2566 (offline) Monday, October 03 2011 @ 09:49 PM CDT



veronica2566 

Junior
Registered: 06/23/10 Posts: 24



