## Q&A - PSLE Math

### Re: Q&A - PSLE Math

hi need help. thanks

Mr Bala can make an average of 15 roti pratas in 10 minutes. His brother can make 1 roti prata in 1 minute. At this rate, how long will it take for both of them to make 100 roti pratas if they start making the roti pratas at the same time?

Mr Bala can make an average of 15 roti pratas in 10 minutes. His brother can make 1 roti prata in 1 minute. At this rate, how long will it take for both of them to make 100 roti pratas if they start making the roti pratas at the same time?

### Re: Q&A - PSLE Math

A tennis ball factory divided the number of tennis balls it manufactured into 4 equal portions and they were sold to 4 different customers.However,one of the customers rejected 1/3 of the tennis balls he bought. what fraction of the tennis balls manufactured was sold?

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- BrownBelt
**Posts:**559**Joined:**Mon Oct 12,**Total Likes:**3

### Re: Q&A - PSLE Math

Hi,lulu2014 wrote:hi need help. thanks

Mr Bala can make an average of 15 roti pratas in 10 minutes. His brother can make 1 roti prata in 1 minute. At this rate, how long will it take for both of them to make 100 roti pratas if they start making the roti pratas at the same time?

Let's try:

In 10 min, they can make 15 + 10 = 25

In 40 min, they can make 100.

Ans: 40 minutes

Cheers

SpeedMaths

.

- alfretztay
- KiasuGrandMaster
**Posts:**1199**Joined:**Sun Sep 12,**Total Likes:**5

### Re: Q&A - PSLE Math

(1 / 3) x (1 / 4) = (1 / 12)lulu2014 wrote:A tennis ball factory divided the number of tennis balls it manufactured into 4 equal portions and they were sold to 4 different customers.However,one of the customers rejected 1/3 of the tennis balls he bought. what fraction of the tennis balls manufactured was sold?

1 - (1 / 12) = (11 / 12).

Ans : 11 / 12

### Re: Q&A - PSLE Math

Mr Ong had only $2 notes and $5 notes in his wallet.

1/3 of the total number of dollar notes was $2 notes.

Mr Ong took out 10 five dollar notes and exchanged them for $2 notes.

In the end, there was an equal number of $2 notes and $5 notes.

Find the total value of money Mr Ong had in his wallet.

TIA n God Bless:)

1/3 of the total number of dollar notes was $2 notes.

Mr Ong took out 10 five dollar notes and exchanged them for $2 notes.

In the end, there was an equal number of $2 notes and $5 notes.

Find the total value of money Mr Ong had in his wallet.

TIA n God Bless:)

### Re: Q&A - PSLE Math

SOS mum wrote:Mr Ong had only $2 notes and $5 notes in his wallet.

1/3 of the total number of dollar notes was $2 notes.

Mr Ong took out 10 five dollar notes and exchanged them for $2 notes.

In the end, there was an equal number of $2 notes and $5 notes.

Find the total value of money Mr Ong had in his wallet.

TIA n God Bless:)

$2. :$5

1 :2 (u)

+ 25. -10

1. : 1. (p)

1u +25=1p

2u-10=1p

2u-10=1u+25

2u-1u=25+10

1u=35

35x$2+70x$5=$420

Mr Ong has $420 in his wallet.

### Re: need to help, thks!

1. The average height of a group pf pupils was 1.68m, When 2 new boys each of height 1.62m joined the group , the average height became 1.67m. How many pupils were there in the group in the end?

2. Albert, Ben and Cass each had some marbles. Albert gave 1/3 of his marbles to Cass. Ben also gave 1/3 of his marbles to Cass. Cass put all the marbles together. She then gave 1/5 of her marbles to Ben.

As a result, Albert and Cass had 20 marbles each and Ben had 15 marbles at the end. How many marbles did each of them have at first?

3. Mrs Tay baked 200 mare walnut cookies than chocolate cookies. She sold 75% of walnut cookies and 40% of chocolate cookies. At the end of the day, there were 43 more walnut cookies than chocolate cookies. How many cookies were there at first?

4. Box A, B and C contained some beads. The ratio of the number of beads in Box A to total number of beads was 2:9. She used 1/3 of the beads in Box B and transferred 1/4 of the beads from Box A to Box C. The ratio of the number of beads left in Box B to the number of beads left in Box C was 4:9. If there were 846 beads in Box B at first, what was the total number of beads left in the end?

2. Albert, Ben and Cass each had some marbles. Albert gave 1/3 of his marbles to Cass. Ben also gave 1/3 of his marbles to Cass. Cass put all the marbles together. She then gave 1/5 of her marbles to Ben.

As a result, Albert and Cass had 20 marbles each and Ben had 15 marbles at the end. How many marbles did each of them have at first?

3. Mrs Tay baked 200 mare walnut cookies than chocolate cookies. She sold 75% of walnut cookies and 40% of chocolate cookies. At the end of the day, there were 43 more walnut cookies than chocolate cookies. How many cookies were there at first?

4. Box A, B and C contained some beads. The ratio of the number of beads in Box A to total number of beads was 2:9. She used 1/3 of the beads in Box B and transferred 1/4 of the beads from Box A to Box C. The ratio of the number of beads left in Box B to the number of beads left in Box C was 4:9. If there were 846 beads in Box B at first, what was the total number of beads left in the end?

### Re: need to help, thks!

A : B+C : A+B+Cjonaandr wrote:1. The average height of a group pf pupils was 1.68m, When 2 new boys each of height 1.62m joined the group , the average height became 1.67m. How many pupils were there in the group in the end?

1.67-1.62=0.05

0.05x2=0.1

1.68-1.67=0.01

0.1/0.01=10

10+2=12

2. Albert, Ben and Cass each had some marbles. Albert gave 1/3 of his marbles to Cass. Ben also gave 1/3 of his marbles to Cass. Cass put all the marbles together. She then gave 1/5 of her marbles to Ben.

As a result, Albert and Cass had 20 marbles each and Ben had 15

marbles at the end. How many marbles did each of them have at first?

A. B. C

End 20. 15. 20(4/5 left)

C3. -5. +5

A2. 20. 10. (2/3left) 25

C2 +5. -5

A. 20(2/3) 15. 20

C1. +10. -10

At first 30. 15. 10

3. Mrs Tay baked 200 mare walnut cookies than chocolate cookies. She sold 75% of walnut cookies and 40% of chocolate cookies. At the end of the day, there were 43 more walnut cookies than chocolate cookies. How many cookies were there at first?

Walnut. Choc

20u+200 20u

-15u-150. -8u

5u+50. 12u

5u+50-->12u+43

7u--> 7

1u-->1

Total at first 40+200=240

4. Box A, B and C contained some beads. The ratio of the number of beads in Box A to total number of beads was 2:9. She used 1/3 of the beads in Box B and transferred 1/4 of the beads from Box A to Box C. The ratio of the number of beads left in Box B to the number of beads left in Box C was 4:9. If there were 846 beads in Box B at first, what was the total number of beads left in the end?

2 : 7 : 9

3B--> 846

Used --> 282

Left--> 564

B left --> 4p--> 564

1p--> 141

C left --> 141x9=1269

B+C+1/4A-->7.5u

7.5u--> 1269+846=2115

1u-->282

9u-->2538

Total beads left-->2538-282=2256

### Re: Q&A - PSLE Math

Can someone please advise on this question? Dont really understand how to solve. ><

Thank you so much in advance!

Mr Teo traveled at 40km/h from town P to town Q. If he increases his speed by 30km/h ,he will take 6 hours lesser to reach his destination.

What was the distance between town P and town Q?

Thank you so much in advance!

Mr Teo traveled at 40km/h from town P to town Q. If he increases his speed by 30km/h ,he will take 6 hours lesser to reach his destination.

What was the distance between town P and town Q?