Q&A - PSLE Math

[Michaelia0816]

Thx, can Can I know the answer?I doing correction, and can't search it as mine do not have adore reader

[Michaelia0816]

Hey, I not sure,pls help pls

[Spongy]

Hi I need help thank you very much!


1. Ann, Ben and Cindy had a total of 640 sweets. The ratio of Ben’s sweets to Cindy’s sweet was 5:4 at first. After Ann and Ben each gave 1/2 of their sweets away, the three children had 420 sweets left. How many sweets did Ann have at first?

2. Jin walked from home to school. For the first 2 minutes, he was walking at an average speed of 40m/min. When he realised that he was going to be late by 3 minutes, he quickly inceased his speed by 10m/min. As a result, he was early by 1 minute. Find the distance between his home to his school.

3. Tom, Faith and Gary took part in a 100m race. When Tom crossed the finishing line, he was ahead of Faith by 20m and ahead of Gary by 40m. Faith and Gary continued to race to the finishing line without changing their speed. How far was Gary from the finishing line when Faith completed the race?

4. Peter had six more 50-cent coins than 20-cent coins. After he used eight 50-cent coins, the value of the 50-cent coins he had was $7.40 more than the value of 20-cent coins he had. How many coins did he have at first?

5. Some plates and cups were packed into blue and red boxes. There were 12 more blue boxes than red boxes. Each blue box contained 120 plates and each red box contained 150 cups. Given that there were 120 fewer plates than cups in total, how many plates were there?

6. 3/5 of Joel’s savings is equal to 2/3 of Mathew’s savings. The difference in their savings is equal to 1/5 of Ben’s savings. Joel saves $35 more than Ben.
(a) Find the ratio of Joel’s savings to Mathew’s savings to Ben’s savings.
(b) Find the total amount of saving of the 3 children.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!



6. 3/5 of Joel's savings is equal to 2/3 of Mathew's savings. The difference in their savings is equal to 1/5 of Ben's savings. Joel saves $35 more than Ben.
(a) Find the ratio of Joel's savings to Mathew's savings to Ben's savings.
(b) Find the total amount of saving of the 3 children.

Hi

wow.. that's quite a bunch..

Q6..

3/5 of Joel's savings = 2/3 of Mathew's savings
6/10 of Joel's savings = 6/9 of Mathew's savings
Joel's savings --> 10 units .......}
Mathew's savings --> 9 units ...} difference = 1 unit
Ben's savings --> 5 units
a) Ratio of Joel's savings : Mathew's savings : Ben's savings
= 10 : 9 : 5

b) Joel saves $35 more than Ben
5 units --> $35, 1 unit --> $7
Total savings --> (10+9+5) x $7 = $168

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!


5. Some plates and cups were packed into blue and red boxes. There were 12 more blue boxes than red boxes. Each blue box contained 120 plates and each red box contained 150 cups. Given that there were 120 fewer plates than cups in total, how many plates were there?

Q5.
Add 12 red boxes so that there are equal number of blue and red boxes.
12 red boxes --> 150 x 12 = 1800 cups
so, there are now 1800 + 120 = 1920 more cups than plates.
for every red box and blue box,
150 - 120 = 30 --> there are 30 more cups than plates
1920/30 = 64 --> there are 64 boxes each
Number of red boxes = 64 - 12 = 52
Number of plates = 64 x 120 = 7680

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!


4. Peter had six more 50-cent coins than 20-cent coins. After he used eight 50-cent coins, the value of the 50-cent coins he had was $7.40 more than the value of 20-cent coins he had. How many coins did he have at first?

Q4.
After using 8 50-cent coins, there are now 2 more 20-cents coins.
Add 2 more 50-cent coins so that there are equal number of 50-cent & 20-cent coins.
2 x $0.50 + $7.40 = $8.40, value of 50-cents coins is $8.40 more than 20-cent coins

$8.40/$0.30 = 28
Number of 20-cent coins = 28
Number of 50-cent coins at first = 28 - 2 + 8 = 34
Total number = 62 --> Peter had 62 coins at first.

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!




3. Tom, Faith and Gary took part in a 100m race. When Tom crossed the finishing line, he was ahead of Faith by 20m and ahead of Gary by 40m. Faith and Gary continued to race to the finishing line without changing their speed. How far was Gary from the finishing line when Faith completed the race?

Q3.
Distance run by Tom : Faith : Gary = 100 : 80 : 60 = 5 : 4 : 3

When Faith completes the race,
Faith : Gary = 4 : 3 = 100 : 75,
Gary has only completed 75m
100m - 75m = 25m, Gary was 25 m from the finishing line.

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!



2. Jin walked from home to school. For the first 2 minutes, he was walking at an average speed of 40m/min. When he realised that he was going to be late by 3 minutes, he quickly inceased his speed by 10m/min. As a result, he was early by 1 minute. Find the distance between his home to his school.

Q2.
increased speed = 40m/min + 10m/min = 50m/min
original speed: increased speed = 40 : 50 = 4:5

ratio of time taken to reach school for the 2nd part of the journey at original speed : increased speed = 5units : 4units

Time taken to reach the school at increased speed is (3+1)= 4 min faster than at original speed
1 unit = 4 min, 5 units = 20 min
Distance to school = (20+2)x40 = 880 m.

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!


1. Ann, Ben and Cindy had a total of 640 sweets. The ratio of Ben's sweets to Cindy's sweet was 5:4 at first. After Ann and Ben each gave 1/2 of their sweets away, the three children had 420 sweets left. How many sweets did Ann have at first?

Q1.
Total number of sweets given away by Ann & Ben = 640 - 420 = 220
Total number of sweets Ann & Ben had at first = 220 x 2 = 440
Number of sweets Cindy had = 640 - 440 = 200
Number of sweets Ben had at first = 5 * 200/4 = 250
Number of sweets Ann had at first = 440 - 250 = 190

cheers.

[Flipper123]

Thanks Cinman for helping with the rombus question. I think this is too difficult for a p6 student. Sigh…