Q&A - P3 Math

[Xiao Hu]

teh_oh:

rrjan:

Would all the maths gurus here kindly help me with these P3 maths questions? A million thanks


Qn 1)Arrange 16 coins on 4 sides of a square so that there are 5 coins on each side. Draw on a square to show your answer.

Qn 2)Mike has enough money to buy 2 pairs of socks. There are 3 pairs on display: blue, green and white. How many ways can Mike buy 2 different pairs of socks?

Qn 3)There are 11 persons who work at the fast food restaurant on weekends. 9 of them work on Saturday and 7 work on Sunday. How many persons work on both Saturday and Sunday?

A million thanks for any kind help rendered

Hi rrjan,

http://i52.tinypic.com/5p7q1.jpg\">

Hi teh_oh, MathIzzzFun,
I also came across Q2 and taught my child but have a different answer. Hope to have clarifications from you.
Assuming no mixing of colors in a pair, then isn't \"BW\" same as \"WB\" ? Is this considered 1 way and not 2 ways?

My reasoning was 3C2 (3 Choose 2)=3.

Listing it out, it will be BG,BW,WG.

May I know what's being taught in school with regards to this kind of question?

TIA.

Humbly,
Xiao Hu

[pojo]

Xiao Hu:

teh_oh:

[quote=\"rrjan\"]Would all the maths gurus here kindly help me with these P3 maths questions? A million thanks


Qn 1)Arrange 16 coins on 4 sides of a square so that there are 5 coins on each side. Draw on a square to show your answer.

Qn 2)Mike has enough money to buy 2 pairs of socks. There are 3 pairs on display: blue, green and white. How many ways can Mike buy 2 different pairs of socks?

Qn 3)There are 11 persons who work at the fast food restaurant on weekends. 9 of them work on Saturday and 7 work on Sunday. How many persons work on both Saturday and Sunday?

A million thanks for any kind help rendered

Hi rrjan,

http://i52.tinypic.com/5p7q1.jpg\">

Hi teh_oh, MathIzzzFun,
I also came across Q2 and taught my child but have a different answer. Hope to have clarifications from you.
Assuming no mixing of colors in a pair, then isn't \"BW\" same as \"WB\" ? Is this considered 1 way and not 2 ways?

My reasoning was 3C2 (3 Choose 2)=3.

Listing it out, it will be BG,BW,WG.

May I know what's being taught in school with regards to this kind of question?

TIA.

Humbly,
Xiao Hu[/quote][quote]Hi rrjan

I gave it a try and these are my answers.

Qn 1)Arrange 16 coins on 4 sides of a square so that there are 5 coins on each side. Draw on a square to show your answer.

O O O O O
---------
O | | O
O | | O
O | | O
---------
O O O O O



Qn 2)Mike has enough money to buy 2 pairs of socks. There are 3 pairs on display: blue, green and white. How many ways can Mike buy 2 different pairs of socks?

3 ways - 1 B+G 2 B+W 3 G+W

Qn 3)There are 11 persons who work at the fast food restaurant on weekends. 9 of them work on Saturday and 7 work on Sunday. How many persons work on both Saturday and Sunday?

O O O O O O O O O O O O
|-------------------------| 9 work on Sat
|------------------| 7 work on Sun
|------------| Therefore 5 work on both Sat and Sun.

I may be wrong. Get a second opinion.
[/quote]Hi Xiao Hu

I agree with you. See my earlier reply.

[teh_oh]

Hi parents,

Thanks for highlighting my mistakes.

[ttyh]

Pls help me. I know I can manually draw it out, but is there a formula for this?

Thanks!

Q; Googol’s clock is faulty. It becomes 6 mins slower after every hour.
He adjusts his clock to show 6am on Tuesday.
a) What time will his clock show on Wednesday at 6am?
b) What time will his clock show next Tues at 6am?

[Xiao Hu]

teh_oh:

Hi parents,

Thanks for highlighting my mistakes.

Hi pojo, teh_oh,
Thanks for clarifying.

Humbly,
Xiao hu

[corneyAmber]

ttyh:

Pls help me. I know I can manually draw it out, but is there a formula for this?

Thanks!

Q; Googol's clock is faulty. It becomes 6 mins slower after every hour.
He adjusts his clock to show 6am on Tuesday.
a) What time will his clock show on Wednesday at 6am?
b) What time will his clock show next Tues at 6am?

(a) tue to wed 6am = 24 hours
Time lag behind = 24 x 6 = 144 mins = 2 hours 24 mins
So time on clock on Wed will be 3:36 am

(b) tue to tue = 7 days = 24 x 7 = 168 hours.
Time lag behind = 168 x 6 = 1008 mins = 16 hrs 48 mins
So time on clock will be Mon 1:12pm

[ttyh]

Thanks Ksi. My mind wasn’t functioning.

[Champion]

Hi! Need help with this P3 Maths Question :thankyou: in advance.


Ann,Ben and Carl had a race.
After ten minutes, Ann had run thrice as far ad Carl.
Ben was 300m ahead of Carl and 480m behind Ann.
(a) How far did Carl run?
(b) if Ann was 430m away from the finishing line, what was the total distance of the race?

Draw model to show your working; give your answer in kilometres and metres.

[Sun_2010]

Giving it a try, on ipad it is difficult to draw model



D _______________________

A. [3u]-------430m------

B. []----480m----

C. [u]–300m–

So
2u = 300m + 480m
u = 390m

Total distance D = 3x390m + 430m
= 1600m
= 1km 600m

[Champion]

Sun_2010:

Giving it a try, on ipad it is difficult to draw model



D _____________________________________________

A. [____________3u_______________]-------430m------

B. [__________________]----480m----

C. [____u_____]--300m--

So
2u = 300m + 480m
u = 390m

Total distance D = 3x390m + 430m
= 1600m
= 1km 600m

:thankyou: Sun_2010 for the assistance rendered; appreciates much! :celebrate: