Tutor MathsGuru: Ask me for your burning Maths questions!

[peapot]

Hi everyone! I have a P2 question which I m not sure how to teach. Pls help me!! Thanks!


9_ _ - 99 = _01

How ah???

[bellerina]

Pls help with a P6 Qs. Thanks!


For a few months, Ng used 1/4 of his wkend playing tennis with his friends & 1/2 of his wkdays working in the office. He used up 115 days on tennis & work.
Another 1/2 of his wkend were spent on shopping & 1/4 of his wkdays were spent having dinner & playing soccer with his friends. He used up a total of 74 days on these activities.
He spent the rest of his time reading at home. How many days did he stay at home?

[Dharma]

peapot:

Hi everyone! I have a P2 question which I m not sure how to teach. Pls help me!! Thanks!


9_ _ - 99 = _01

How ah???

999 - 99 = 900
but answer's ones digit is 1. Therefore, the hundreds digit of the answer must be 8
So, answer is 801
Work backwards

9_ _ - 99 = 801
9_ _ - 99 + 99 = 801 + 99
9_ _ = 900

[autolycus]

bellerina:

Pls help with a P6 Qs. Thanks!


For a few months, Ng used 1/4 of his wkend playing tennis with his friends & 1/2 of his wkdays working in the office. He used up 115 days on tennis & work.
Another 1/2 of his wkend were spent on shopping & 1/4 of his wkdays were spent having dinner & playing soccer with his friends. He used up a total of 74 days on these activities.
He spent the rest of his time reading at home. How many days did he stay at home?

Wkends spent = 1/4 + 1/2 = 3/4.
Wkdays spent = 1/2 + 1/4 = 3/4.

That means he spends 3/4 of his week doing stuff. So the 115 days + 74 days = 3/4 of his days.

Time left = 1/4 overall
Days left must be 1/3 of the time spent, since that time was 3/4.

Hence time at home = 1/3 x 189 = 93 days.

In fact we can figure out that this is a period of roughly 10 months.

[peapot]

Thank Dharma,


But my gal haven’t grasp the concept that 999-99 is 900 yet. Any other easier way, I wonder?

[Dharma]

peapot:

Thank Dharma,


But my gal haven't grasp the concept that 999-99 is 900 yet. Any other easier way, I wonder?

Actually I chose 999 to minus 99 to show the hundreds place of the answer to the question cannot be 9 because the ones digit of the answer is 1

You may wish to break up the number 999 into it's hundreds, tens and ones.
Do the same for 99. Then deduct 99 from 999

999 = 900 + 90 + 9
99 = 90 + 9

999 - 99 = 900

[peterch]

Please help me with P5 math :


Ms Tham distributed a packet of sweets among a group of pupils.
If she gave out 11 sweets to each pupil, the last pupil received only 6 sweets.
If she gave out 8 sweets to each pupil, there would be 34 sweets left over.
A. How many pupils were there?
B. How many sweets were there?

Thanks in advance

[hashroop]

Pls help :

The volume of a rectangular tank is 162litters. It’s length is twice its breadth and 2/3 its height. Find the length of the tank.
Maths guru kindly help.
Greatly appreciated

[Yu Xuan]

peterch:

Please help me with P5 math :


Ms Tham distributed a packet of sweets among a group of pupils.
If she gave out 11 sweets to each pupil, the last pupil received only 6 sweets.
If she gave out 8 sweets to each pupil, there would be 34 sweets left over.
A. How many pupils were there?
B. How many sweets were there?

Thanks in advance

By giving each pupil 3 sweets more, a total of 39 sweets (34 + 5) is required.

a) Hence, the number to students is
39 / 3 = 13

b) 13 * 8 + 34 = 138

Yu Xuan

[iFruit]

hashroop:

Pls help :

The volume of a rectangular tank is 162litters. It's length is twice its breadth and 2/3 its height. Find the length of the tank.
Maths guru kindly help.
Greatly appreciated

Let breadth = b
length = 2b
height = 3/2 (2b) = 3b

volume = length x breadth x height = 2b x b x 3b = 6xbxbxb = 162---->b x b x b=27 = 3x3x3----> b=3

length = 2b =6

HTH.