Tutor MathsGuru: Ask me for your burning Maths questions!
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Total
100 percent
spent:save
$320:100%-320
new spent:new save
55%of 320: 160% of (100%-320)
176: 160%-512
176+ 160% -512=100%
60%=336
100%=$560 -
Hi firebird,
http://www.orlesson.org/orp/09Ma/2009-P6-Math-SA2-HenryPark.pdf
Paper 1 Q16
Write 3 thousands, 4 ones, 6 tenths and 18 hundredths as decimal.
3000+4+6(0.1)+18(0.01)
3000+4+0.6+0.18
3004.78
Paper 1 Q19
The diagram below is made of 4 semicircles. The diameter of the biggest semicircle is 28 cm. Find the perimeter of the shaded figure. Express the answer in terms of ∏.
Perimeter of the shaded figure =½x∏x28 + ½x∏x28 = 28∏ cm
Paper 1 Q21
The average of 3 different odd numbers is 5. What is the largest possible value of one of the numbers?
Sum of 3 different odd numbers is 3x5 = 15
15 = 11+3+1
Largest possible value of one of the numbers is 11
Paper 1 Q29
The ratio of the number of girls to the number of boys in the library was 4: 5. After a group of boys entered the library, 40% of the new total number of children were girls. What percentage increase in the number of boys?
Before
B : G
5 : 4
After
B : G
6 : 4
Increase in terms of ratio for boys = 1 unit
Percentage increase in the number of boys = 1/5x100% = 20%
Paper 2 Q6
Sharon bought M pens and 3 note books for $5. Each pen cost 40 cents. Express the cost of 1 notebook in terms of M.
Cost of 1 notebook in terms of M = $(5-0.4M)/3
Paper 2 Q12
Tank P was filled with water as shown in the diagram below. Water was then poured from Tank P to Tank Q until the height of the water level in Tank P became twice that of the water level in Tank Q. Find the volume of water in Tank Q. Give your answers in litres.
Assume new height in Tank Q be H.
Volume of water in Tank P = 40x30x2H = 2400H cm³
Volume of water in Tank Q = 100x20xH = 2000H cm³
2400H+2000H = 55x40x30
4400H = 66000
H = 15 cm
Volume of water in Tank Q = 100x20x15 = 30000 cm³ = 30 litres
Paper 2 Q15
A librarian counted the number of adults in the library and found that 2/5 of the number of women was equal to 2 times the number of men. When another 12 men entered the library and 45 women left the library, the ratio of the number of women to men became 5:2.
a) What was the ratio of the number of women at first to the number of the men at first? Give your answer in its simplest form.
b) Find the number of women at first.
Before
Women : 5 units
2/5 of the women = 2/5x5 = 2 units
2 units of women is 2 times the number of men, so men would be 1 unit.
a) Ratio of the number of women at first to the number of the men at first = 5 : 1
Draw a model:
Men
[u][6][u][6]
Women
[u][6][u][6][u][6][u][6][u][6][45]
Shade the two blocks of [6] for men to represent 12 men due to enter the library to show the initial scenario. (Women : Men = 5 : 1)
(2 units)x5 = (5 units) + (6x5) + 45
10 units = 5 units + 30 + 45
15 units = 75
1 unit = 5
b) Number of women at first = 5 units +75 = 5(15)+75 = 75+75 = 150
Hope this helps while waiting for Mathsguru's detailed model solutions.
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Herbie:
BeforeAmy spent $320 of her income and saved the rest.
When she decreased her spending by 45%, her savings increased by 60%
How much was her income?
Spent : $320 (100%)
Saving : ? (100%)
After
Spent : $176 (55%)
Saving : ? (160%)
$320+100% saving = $176+160%saving
60% saving = $144
100% saving = $240
Income = Spending+Saving
Before: Spent = $320 (100%) + Saving = $240 (100%) = $560
After: Spent = $176 (55%) + Saving = $384 (160%) = $560
Hope that I don't confuse you and let's wait for Mathsguru's solution.
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Dear Vanilla Cake
Many many thanks for your answers. They are very helpful.
With best regards
firebird -
Hi!
Help needed!
These are P5 qtns:
Q1 Tom and Jerry each has some money. If Tom spends $90 per day and Jerry spends $45 per day, Tom will have $1100 left when Jerry has spent all his money. If Tom spends $45 each day and Jerry spends $90 each day, Tom will have $1700 left when Jerry has spent all his money. How much did Jerry have?
Q2 Andy, Betty, Candy and Danny each have some money. The amount of money Andy has is 1/3 of the total amount of money Betty, Candy and Danny have. The amount of money Betty has is 1/4 of the total amount of money Andy, Candy and Danny have. The amount of money Candy has is 1/5 of the total amount of money Andy, Betty and Danny have. If Danny has $1725, how much do they have altogether?
TIA
God Bless! -
Cheerfuldad:
See http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6373&postdays=0&postorder=asc&start=780Hi!
Help needed!
These are P5 qtns:
Q1 Tom and Jerry each has some money. If Tom spends $90 per day and Jerry spends $45 per day, Tom will have $1100 left when Jerry has spent all his money. If Tom spends $45 each day and Jerry spends $90 each day, Tom will have $1700 left when Jerry has spent all his money.
Q2 Andy, Betty, Candy and Danny each have some money. The amount of money Andy has is 1/3 of the total amount of money Betty, Candy and Danny have. The amount of money Betty has is 1/4 of the total amount of money Andy, Candy and Danny have. The amount of money Candy has is 1/5 of the total amount of money Andy, Betty and Danny have. If Danny has $1725, how much do they have altogether?
TIA
God Bless! -
Dear maths guru
Please help me on the following:
Mrs Ong took 10 hours to drive from Town A to Town B.
Mr. Soong drove along the same route but took 8 hours to complete the journey. The difference in their average speed was 10 km/h.
(a) What was Mrs Ong’s average speed?
(b) Find the distance between Town A and Town B.
Thank you
firebird -
firebird:
a)Dear maths guru
Please help me on the following:
Mrs Ong took 10 hours to drive from Town A to Town B.
Mr. Soong drove along the same route but took 8 hours to complete the journey. The difference in their average speed was 10 km/h.
(a) What was Mrs Ong's average speed?
(b) Find the distance between Town A and Town B.
Thank you
firebird
mr soong finish the drive 2 hrs faster than mrs ong.
difference in speed =10km/h
after driving for 8 hrs.
mr soong finish the drive.
mrs ong is 8 x 10=80km behind mr soong or behind the finishing line
mrs ong need to use 2 more hrs to cover up this 80 km
so mrs ong average speed is 80/2=40km/hr
b)
mrs ong use 10 hrs
so the distance is 10 x 40 =400km -
Dear Guan Hui
Many thanks for the answer.
With best regards
firebird -
firebird:
haha np,Dear Guan Hui
Many thanks for the answer.
With best regards
firebird
solving question for you at this hour is a pleasant break from my own muggingXD
so... thank you
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