Q&A - PSLE Math

[charsen]

tianzhu:

zanen:

hello can help me with this qns 10 workers can complete a painting job. If there are 2 more workers, the painting job will be completed 6 days sooner. If the same painting job were to be done 21 days earlier, how many additional workers are needed?

Hi

A point to note, the more the number of workers, the fewer the number of days.

Increase in 2 workers ------- 6 days earlier

Increase in 1 workers ------- 3 days earlier

Increase in 7 workers ------- 21 days earlier

Additional workers ------- 7

Best wishes

Hi Tianzhu,
This is my worked solution.
12 workers----->6 days earlier.
Total amount of mandays reduced--->10x6=60 mandays.
compensted work---->2 additional workers
Days covered to complete compensated work---->60/2=30
and originally, the 10 workers work for 30 + 6 = 36 days,

Total work needed for the painting job = 12 x 30 = 360 man- days.

To work 21 days less means working for 36-21 = 15 days

Number of workers needed = 360 man-days / 15 days = 24 workers

So, additional worker needed = 24 - 10 = 14

cheers

[Zhu99]

ximinful:

Pls help with the following question.

Min had 3 times as many beads as Ahmad. Min packed all her beads equally into 42 boxes while Ahmad packed all his beads into 56 bags. There are 93 more beads in each box than in each bag. How many beads did min and Ahmad have in total?

Tia :thankyou:

A - 1 u ---> 56 Bags

1 Box ---> 1 Bag + 93

M - 3 u ---> 42 Boxes = 42 x (1 Bag + 93)
= 42 Bags + 3906

42 Bags + 3906 ---> 3 x 56 Bags
126 Bags ---> 3906

56 Bags ---> 3906/126 x 56 = 1736

4 u ---> 1736 x 4 = 6944

Min and Ahmad had 6944 beads in total.

[tianzhu]

charsen:

Hi Tianzhu,

This is my worked solution.

Hi charsen

Yes, you are correct.

Thank you for highlighting the error.

Best wishes

[2632parent]

Need help on the following question


1) Mr Tan had some apples and oranges in the ratio 4:5. After selling 170 apples and 25% of the oranges, the ratio of the apples to oranges left became 1:2. What was the number of fruits Mr Tan had in the end?

Thank you

[tianzhu]

2632parent:

Need help on the following question


1) Mr Tan had some apples and oranges in the ratio 4:5. After selling 170 apples and 25% of the oranges, the ratio of the apples to oranges left became 1:2. What was the number of fruits Mr Tan had in the end?

Thank you

Hi

At first

Apples ----- 16 units

Oranges ------ 20 units

Change

Apples ----- 170

Oranges ------ 5 units (25%)

In the end

Apples ----- 1 part

Oranges ------ 2 parts

16 units – 170 ------ 1 part

(x2)
32 units - 340 ------- 2 parts

15 units ------- 2 parts

Equalising the parts

32 units – 340 ------- 15 units

1 unit ------ 20

Number of fruits in the end ------- (16*20 – 170) + (15*20) ------- 450

Best wishes

[jarenchuatw]

Got 2 questions here needing help to solve:


Q1 A shopkeeper had some track shoes. 3/7 of them were brand X, 1/4 of the remainder were Brand Y and the rest were Brand Z. The ratio of the number of pairs of Brand X sold to the number of Brand Y to the number of Brand Z sold was 1:2:4. He sold 1/5 of all the shoes and was paid &840. How many pairs of Brand Z had he at
first?

Q2 see image attached

[zombie]

Hello, can someone please help me to solve these percentage questions? :oops:


1)John had 55% as many stickers as marbles. After he gave an equal number of stickers and marbles to Rick, he had 5/8 as many stickers as marbles. How many stickers and marbles did he give away if he had 168 marbles in the end?

2)Anne, Ben and Chris shared the cost of their seafood dinner. Anne paid 40% the total amount and Ben paid 30% of what Anne and Chris paid. If Ben paid $36 less than Chris, how much did Anne pay?

3)Mr Low had 40% more cows than sheep. After he sold 375 cows and bought 375 sheep, he had 80% lesser cows than sheep. How many sheep did he have in the end?

4)Adam has 30% as many stickers than Ben and 25% more cards than Chris. If they have a total of 462 stickers, how many stickers does Chris have?

5)Kelly had 40% as much money as Mandy. After Mandy spent $66 on a dress, the percentage of Kelly’s money increased to 60%. How much money did Kelly have?

6)There were 40% of girls in the Science Club. After another 30 girls joined the Science Club, the percentage of girls increased by 15%. How many pupilswere there in the club at the end ?

7)There were 165 more chickens than ducks on a farm. If 60% of the chickens and 20% of the ducks were sold, the number of chickens left will be twice the number of ducks left. How many chickens were sold?

8)John had 55% as many stickers as marbles. After he gave an equal number of stickers and marbles to Rick, he had 5/8 as many stickers as marbles. How many stickers and marbles did he give away if he had 168 marbles in the end?

Thank you !

[2632parent]

Hi tianzhu how do you get 16u for the apples and 20u for the orange. Thank you.

[tianzhu]

2632parent:

Hi tianzhu how do you get 16u for the apples and 20u for the orange. Thank you.

Hi

Apples:Oranges ------- 4:5 ------ 16:20

25% ------ 1/4

A common multiple for 4 and 5 is 20.

Best wishes

[tianzhu]

jarenchuatw:

Got 2 questions here needing help to solve:


Q1 A shopkeeper had some track shoes. 3/7 of them were brand X, 1/4 of the remainder were Brand Y and the rest were Brand Z. The ratio of the number of pairs of Brand X sold to the number of Brand Y to the number of Brand Z sold was 1:2:4. He sold 1/5 of all the shoes and was paid &840. How many pairs of Brand Z had he at
first?

Q2 see image attached

Hi

For Q1, I think some information might be missing.The amount of money earned for each pair of shoes for different brands is required.

For Q2, please attach the image.

Best wishes