Q&A - PSLE Math

[tianzhu]

looking4Tutor:

Appreciate some help for these 2 questions -

http://i53.tinypic.com/117en84.jpg\">

Hi

A quick one for Q16.

You may use MD or UM.

Adila ----- 100 units
Michelle ------ 160 units
Usha ----- 104 units (35% fewer than M)

M and A gave some cards to U in the ratio 3:1

U ---- 1.5*104 ----- 156
Increase in number of units ----156 -104 -----52

M -----39 units
A -----13 units

In the end

M ------ 160 – 39 ------121 units
A ------ 100 -13 ------ 87 units

121 – 87 ----- 34
34 units ------238
1 unit ------ 7

M gave (39*7) or 273 cards to U.

Best wishes

[MathIzzzFun]

looking4Tutor:

Appreciate some help for these 2 questions -


http://i53.tinypic.com/117en84.jpg\">

TIA

hi

Q16....

http://i56.tinypic.com/288rtk7.jpg\">

cheers.

[looking4Tutor]

Thank you very much, MathIzzzFun and tianzhu.

[tianzhu]

Heeheehaha:

Dear Tianzhu,
Can u explain in more detail how to get answer (a) 4:3;

Hi

A student needs to recognise that the bars showing the number of boys and girls are of different kind and measure.

MD is a neat way of solving such question.

As usual I’ve drawn more MD than necessary to show the flow of events. Once a student becomes more familiar with such questions, he may consolidate some of the steps.

All the best for PSLE 2011.

Best wishes

http://farm7.static.flickr.com/6088/6138927097_afb22f2104_z.jpg\">

[tianzhu]

looking4Tutor:

Thank you very much, MathIzzzFun and tianzhu.

Hi

You're welcome.

Best wishes

[benleetube]

Hi all, can anyone help me with the part (a) of this question?

http://i.imgur.com/vD2dX.png\">

Thanks a lot!

[MathIzzzFun]

benleetube:

Hi all, can anyone help me with the part (a) of this question?

http://i.imgur.com/vD2dX.png\">

Thanks a lot!

Hi

This was discussed in an earlier post..

http://i54.tinypic.com/2r25ete.jpg\">

cheers.

[Vanilla Cake]

Hi MathIzzzFun,


There are 2 different answers given for these 2 questions from 2011 CHIJ St. Nic P6 Prelim Maths. Could you pls confirm the correct answers? No need to type out the worked solutions for them.
TIA for your time plus effort & cheers.

Paper 2 Q3
Sheela was 25 min late for a movie. She was at the cinema at 8.15 p.m. If the duration of the movie was 137 min, at what time did the movie end?
Leave your answer in the 24-hour clock.
2 different answers were given: 2107 or 2207

Paper 2 Q18
A rectangular tank measuring 40 cm by 30 cm by 40 cm was 1/6 filled with water. At 0930 h, Tap X with water flowing out at a rate of 3 l per minute was turned on. At 0932 h, Tap Y was turned on to drained water out of the tank at a fixed rate. At 0943 h, the tank was 75% filled with water. At what time would the tank be filled to the brim?
2 different answers were given: 0949 h or 0954 h

[MathIzzzFun]

Vanilla Cake:

Hi MathIzzzFun,


There are 2 different answers given for these 2 questions from 2011 CHIJ St. Nic P6 Prelim Maths. Could you pls confirm the correct answers? No need to type out the worked solutions for them.
TIA for your time plus effort & cheers.

Paper 2 Q3
Sheela was 25 min late for a movie. She was at the cinema at 8.15 p.m. If the duration of the movie was 137 min, at what time did the movie end?
Leave your answer in the 24-hour clock.
2 different answers were given: 2107 or 2207

Paper 2 Q18
A rectangular tank measuring 40 cm by 30 cm by 40 cm was 1/6 filled with water. At 0930 h, Tap X with water flowing out at a rate of 3 l per minute was turned on. At 0932 h, Tap Y was turned on to drained water out of the tank at a fixed rate. At 0943 h, the tank was 75% filled with water. At what time would the tank be filled to the brim?
2 different answers were given: 0949 h or 0954 h

Hi

Paper 2 Q3 - 2207
Movie started at 8.15pm - 25min = 7.50pm or 1950 h
137 min = 2h 17 min, movie ended at 1950 + 2h 17min = 2207 h

Paper 2 Q18 - 0949 h
check points:
Full volume = 48l
0930 h, volume of water in tank = 8l
0932 h, volume of water in tank = 14l (+ 3l/min x 2min = 6l)
0943 h, volume of water in tank = 36l (increase of 22l in 11 min ie + 2l/min, so tank Y draining at 1l/min)

Volume left to fill = 12l, 12l / 2l/min = 6min

0943 h + 6 min = 0949 h

cheers.

[MathIzzzFun]

looking4Tutor:

Thank you very much, MathIzzzFun and tianzhu.

u r welcome

cheers.