Tutor MathsGuru: Ask me for your burning Maths questions!

[maths6a]

super star:

HI MATHS GURU

Please help me with this problem.At present,ronald is 3 times as old as his sister.In 22 years time,ronald's age will be 19 years less than twice his sister's age.how old is ronald?

RONALD IS 9 YRS OLD

[maths6a]

super star:

Please help me with tis problem

Tom &jerry went shopping with a total of $198.Tom had $ 10 more than jerry .Tom spent 25% as much money as jerry.after which,he had twice as much money left as jerry.
(a)how much money did tom bring for shopping?
(B)how much money had tom left after shopping?

(198 + 10)/2 = 104 Tom (a)
198 - 104 = 94 for Jerry

T 104 - 1 unit ---- 2
J 94 - 4 units -----1

2(94 - 4units) ------104 - 1 unit
188 - 8units ---- 104 - 1 unit
7 units ---- 84
1 unit ---- 12 spent by tom
104 - 12 = 92 (b)

[kancheongmum]

Dharma:

Almighty:

Hi all,

Can anyone help me on this probelm..Is the answer 126cm2

http://www.postimage.org/image.php?v=aV6VnHi

Correct.

Hi Dharma how do you get the answer 126 cm2. Looking at the fig I think is 120 cm2. Pls adv if I am wrong

[maths6a]

super star:

HI MATHS GURU

please help me.The mass of a box containing 3 files was 10.2kg.Later,Ali added 2 more files & 3 books into the box and the mass of the box and its contents became 19 kg .if the mas of one file was four times the mass of a book,find the mass of the box when empty (leave your answer in kg).

Box + 3 F = 10.2 ---- Box + 12 B =10.2 Eq 1
Box + 5 F + 3 B = 19 ---Box + 20 B + 3 B = 19 Eq 2
Eq 2 minus Eq 1 -----11 B = 8.8
1B = 0.8 kg
10.2 - 12 x 0.8 = 0.6 kg (Mass of empth box)

[kancheongmum]

Tang:

mathsguru:

[quote=\"biscuitqueen\"]Hi there, please help me solve this Maths questn for my daughter.

I have no idea how to solve. Thanx!

Mary and Ken travelled from Town A to Town B. Mary left Town A at 0915 and took 4h to reach Town B. Ken left Town A at 1000 and took 2h 45min to reach Town B. At what time did Ken pass Mary?

Hi Biscuitqueen,

Here's my solution. Hope it helps!

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=gxbp40J

Hello,

I believe this is the 3rd time I am highlighting the same issue in this forum. For the benefit of those taking PSLE 2010, I will repeat it for the very last time. Please note that the below statement will be marked wrong.

10 am + 1 h 39 min = 11.39 am

You will easily lose 1 mark for mixing Time with Duration.[/quote]Hi Tang
Pls adv how should the student write the statement. My DS has been writing this way since P4 till now P6. The teachers did not mark him wrong.

[maths6a]

kancheongmum:

Dharma:

[quote=\"Almighty\"]Hi all,

Can anyone help me on this probelm..Is the answer 126cm2

http://www.postimage.org/image.php?v=aV6VnHi

Correct.

Hi Dharma how do you get the answer 126 cm2. Looking at the fig I think is 120 cm2. Pls adv if I am wrong[/quote]Yes 126 is correct after looking at actual diagram. Sorry about that.

[verykiasu2010]

…

[Dharma]

kancheongmum:

Dharma:

[quote=\"Almighty\"]Hi all,

Can anyone help me on this probelm..Is the answer 126cm2

http://www.postimage.org/image.php?v=aV6VnHi

Correct.

Hi Dharma how do you get the answer 126 cm2. Looking at the fig I think is 120 cm2. Pls adv if I am wrong[/quote]
Hi kancheongmum,

If we shift the shaded quadrant the top right hand corner of the rectangle to the bottom left handed corner so that it fits into the unshaded quadrant there.

We have a figure which consist of an unshaded square(top right hand) within rectangle ABCD.

Now draw a vertical line downwards from the top left hand corner of the unshaded square. So sorry I'm unable to draw it out cause I replying using my I-phone.

We do not know the of the square, so we call it 1u

Shaded area
= 10 x ( 5 + 1u) + 5 x 1u
= 50 + 15u

15u + 50 = 110
15u = 60
1u = 4

Area of square = 4 x 4 = 16
Area of Rectangle ABCD
= Shaded area + Area of square
= 110cm2 + 16cm2
= 126cm2

[Almighty]

Dharma:

kancheongmum:

[quote=\"Dharma\"]
Correct.

Hi Dharma how do you get the answer 126 cm2. Looking at the fig I think is 120 cm2. Pls adv if I am wrong

[/quote]Thanks Dharma and others!!

[CJM]

hi all, pls help with this question :


A large water tank has two inlet pipes ( a large one and a small one ) and one outlet pipe. it takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 4 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 7 hours.

What fraction of the tank ( initially empty ) will be filled in 2.27 hours if all three pipes are in operation? Give your answer to two decimal places.