Q&A - PSLE Math

[tianzhu]

Ngserene617:

2. Shelly has some vanilla and chocolate sweets in her bag. If she adds 20 vanilla sweets into the bag, the percentage of vanilla sweets in the bag becomes 40%. If she adds 30 chocolate sweets in the bag, there will be 70% of chocolate sweets in the bag. How many vanilla sweets and chocolate sweets does she have?

Hi

A similar question has been discussed before.

Best wishes

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[tianzhu]

Ngserene617:

1. Alicia had 20% more stickers than Randy. Then Alicia gave away 30% of her stickers to her sister. Randy received 28 stickers from Peter. As a result, Randy now had 25% more stickers than Alicia.
How many stickers did Alicia have at first?

Hi

You may use MD or choose to work using units.

At first
Alicia ------- 120 units
Randy ------ 100 units.

Then Alicia gave away 30% of her stickers to her sister. Randy received 28 stickers from Peter.

Alicia ------- 84 units
Randy ------ 100 units + 28

In the end
Alicia ------- 84 units
Randy ------ 105 units (25% more than Alicia)

105 units ------ 100 units + 28
5 units ------ 28

120 units ------ 672 (Alicia’s number of stickers at first)

Best wishes

[tianzhu]

Ngserene617:

3. On average, a bakery sells 500 fish fillet buns at$1.50 each day. When each bun increases by 20%, the total sales volume drops by 25%.
A. Find the new price of each bun.
B. find the number of buns sold at the new price.
C. What is the percentage change in the amount collected from the sales with the increase in the price?
D. Find the percentage discount required on the new price to adjust the price to its original level

Hi

Sales volume refers to the number of units sold in a certain period.

Fish fillet bun ------- $1.50
When increases by 20%, its new price is S1.80

Number of buns sold at new price ------ 500*3/4 ------ 375

Amount collected at new price ------- 375*1.8 ------ 675
Amount collected at first ------ 500*1.5 ------750
Decrease in amount ------ 750 – 675 ----- 75
% change ------ 75/750*100% ------ 10%

Percentage discount ------- 30/180*100% ------ 16 2/3%

Best wishes

[Winx5015]

Ricky started driving from City A to City B at 1130 hours travelling at an average speed of 88km/h. Half an hour later, Peter started driving from City A to City B at an average speed of 6km/h faster than Ricky.

(a). If Peter reached City B at 2000 hours, what was the distance between City A and City B?
(b). At what time would Peter start to overtake Ricky?

Thanks.

[tianzhu]

Winx5015:

Ricky started driving from City A to City B at 1130 hours travelling at an average speed of 88km/h. Half an hour later, Peter started driving from City A to City B at an average speed of 6km/h faster than Ricky.

(a). If Peter reached City B at 2000 hours, what was the distance between City A and City B?
(b). At what time would Peter start to overtake Ricky?

Thanks.

Hi

Start by drawing a distance/time pictorial representation.

Ricky had a head start of 88*1/2 ------ 44km

Peter’s speed ------ 88+6 ------ 94 km/h

Peter took 8h to travel from City A to City B (1200h ----- 2000h)

Distance ------- 94*8 ------- 752 km

Time to catch up ------- 44/6 ------ 7 1/3 h

Peter started to overtake Ricky at 1920 h

Best wishes

[Michaelia0816]

Tianzhu I do not need the MD. Thank for your effort!

[Michaelia0816]

Help help!!!

Mary has 20 more dolls than Cindy. After Mary have 2/5 of her dolls to Cindy, Mary has 1/2 as many dolls as Cindy. How many dolls do they have together?

[Michaelia0816]

Is the answer 180?

[superksmum]

Pls help!


Dave and Carl had 186 marbles altogether. Dave had 6 more marbles than Carl. In a game, Dave lost 25% as many marbles as the number of marbles Carl lost to Eng Hong. Dave was then left with twice as many marbles as Carl. How many marbles did Dave have after the game?

Thank you.

[tianzhu]

Michaelia0816:

Help help!!!

Mary has 20 more dolls than Cindy. After Mary have 2/5 of her dolls to Cindy, Mary has 1/2 as many dolls as Cindy. How many dolls do they have together?

Hi

If \"have\" is changed to \"gave\", your answer of 180 is correct.

Best wishes