Q&A - PSLE Math

[Winx5015]

Hi,


Got problem with the following question. Pse help.

A coin box contained some 10-cent coins and 50-cent coins in the ratio of 7:2. Peter took out eight 10-cent coins and put in another twenty 50-cent coins into the box. There are now half as many 10-cent coins as 50-cent coins.
(a) How many 10-cent coins were in the box at first?
(b) What is the total value of all the coins in the box now?

Thanks!

[tianzhu]

Winx5015:

Hi,


Got problem with the following question. Pse help.

A coin box contained some 10-cent coins and 50-cent coins in the ratio of 7:2. Peter took out eight 10-cent coins and put in another twenty 50-cent coins into the box. There are now half as many 10-cent coins as 50-cent coins.
(a) How many 10-cent coins were in the box at first?
(b) What is the total value of all the coins in the box now?

Thanks!

Hi

You may use \"Units and Parts\"

At first
10-cent coins: 50-cent coins ------- 7u:2u

Change
10-cent coins: 50-cent coins ------- -8 :+20

In the end
10-cent coins: 50-cent coins ------- 1p:2p


Equalise the parts.

(7u - ----- 1p
(x2)
14u - 16 ------ 2p

(2u + 20) ----- 2p

14u - 16 ----- 2u + 20
12u ----- 36
1u ------ 3

Number of 10-cent coins were in the box at first ------ 3*7 ------ 21

Now
Number of 10-cent coins ------ 13
Number of 50-cent coins ------- 26

Total value ------- $14.30

Best wishes

[2DMommy]

Please help me with these questions :


1) Benita and Mildred shared a box of laminating sheets. If Benita were to give 25% of her share to Mildred, Benita would have half of Mildred's final share. If Benita were to give 16 laminating sheets to Mildred, Benita would have 54 fewer laminating sheets than Mildred. If they were to pack all their laminating sheets into boxes of 25 each, what is the least number of boxes required to pack all of them ?

2)Jan and Kay had equal number of sweets and equal number of chocolates. Jan ate 12 sweets and Kay ate 18 chocolates and then the ratio of Jan's sweets to chocolates became 1 : 7 and the ratio of Kay's sweets to chocolates became 1 : 4. How many sweets did Jan have at first?

3)The tickets for a show are priced at $10 and $5. The number of ten-dollar tickets available is 1 half times the number of five-dollar tickets. 5 out of 6 ten-dollar tickets and all the five-dollar tickets were sold. The amount of money collected from the sale of the tickets were $5600. How much more would have been collected if all the tickets were sold ?

:thankyou:

[Bunny27]

I’m not sure about tis question…

Colin and Karin save $2378.1/6 of Colin’s savings is $41 more than 1/7 of Karin’s savings. Find the ratio of Colins savings to Karin’s savings. Express your answer in the simplest form.

TIA

[Winx5015]

Hi tianzhu,


Thanks for your solution.

Have a nice weekends

[jewelbox]

Hi tianzhu

Thank you so much for the solutions and teaching how to use units and parts.:)

[tianzhu]

Winx5015:

Hi tianzhu,


Thanks for your solution.

Have a nice weekends

Hi

You're welcome.

Have a good weekend too.

Best wishes

[tianzhu]

jewelbox:

Hi tianzhu

Thank you so much for the solutions and teaching how to use units and parts.:)

Hi

You're welcome.

Your username reminds me that my jewelbox is very empty, so sad.

While MD may be used to solve your question, I think UP is more efficient.

Have a good weekend.

Best wishes

[happyheart]

Hi Tianzhu,


Thank you for helping many of us here in solving questions. I would like to seek your advice on any good approach to tackling Maths as a subject. My DS has super good memory when it comes to geography, history, current affairs, events etc. But when it comes to remembering Mathematics concept, strategy and rules, he is like a goldfish with 3 seconds memory! He forgets them so easily! This make learning progress very slow as we have to back track almost every topic that he has been taught.

[jtparent]

Hi,


Pse assist on the following q:

q1 : The ratio of the num of xavier’s stickers to the num of Yvonne’s stickers to the num of Zack’s stickers was 4:6:7 at first. When Xavier bought another 35 stickers & Yvonne lost 27 stickers, Xavier & Yvonne had the same num of stickers. How many more stickers would Zack have to buy in order to have twice as many stickers as Yvonne?

q2: On Mr Chan’s farm, 70% of his fowls were chickens & the rest were ducks. When he bought another 108 more ducks, the num of ducks on his farm increased by 40%. Afer selling some chickens, he had an equal num of chickens & ducks left. How many chickens did Mr Chan sell?

q3: At first, Chenxu had 2/3 as many stickers as Weiwei. After Chenxu bought another 3 stickers and Weiwei lost 9 stickers, Chenxu had 5/6 as many stickers as Weiwei. Find the num of stickers Chenxu had at first?

TIA