Q&A - P5 Math

[tianzhu]

panic_mum:

Hi how do you get 1440?

Hi

There are a total of 1430 red, blue, green and yellow marbles in a box.

9 units – 40 + 30 ------ 1430

9 units ------ 1440

Best wishes

[tianzhu]

Trevortan:

4. In a basket, the ratio of the number of pears to the number of apples is 3:4. If I add another 12 apples, there would be 1/2 as many pears as apples. How many pears and apples are there in the basket at first?

Hi

Before
Pears:Apples ------ 3:4

After
Pears:Apples ------ 1:2 ------ 3:6

The number of pears stays the same; make its units the same before and after.

2 units ------ 12

1 unit ------ 6

Pears@first -------- 3*6 ------- 18

Appless@first -------- 3*6 ------- 24

Total ------- 42

Best wishes

[tianzhu]

Trevortan:

5. Alex, Terence, Cherry and Daniel bought a present for their friend. Alex paid 1/4 of the amount paid by Terence, Cherry and Daniel. The ratio of the amount paid by Terence to the amount paid by Cherry and Daniel was 3:5. The ratio of the amount paid by Cherry to the amount paid by Daniel was 3:7. Given that Alex paid $12 less than Daniel, find the cost of the present.

Hi

It helps to draw a MD. I’ll give you some pointers due to time constraints.

A:T+C+D ------ 1:4 ----- 4:16

T:C+D ------ 3:5 ------ 6:10

C:D ------ 3:7

3 units ----- 12

1 unit ----- 4

Cost of present ------ 20*4 ------ 80

Best wishes

[tianzhu]

Trevortan:

3. Jacintha and Isabel shared a number of cookies in the ratio 2:1. The number of cookies that Jacintha had was 1/4 of the number of cookies Evelyn had. If Evelyn had 63 more cookies than Isabel, how many cookies did the three of them have altogether?

Hi

You may use MD or work using units.

Jacintha and Isabel shared a number of cookies in the ratio 2:1.

J ------ 2 units
I ------ 1 unit

The number of cookies that Jacintha had was 1/4 of the number of cookies Evelyn had.

E ------- 8 units

7 units ------ 63 (If Evelyn had 63 more cookies than Isabel?)

1 unit ------ 9

Total number of cookies ------- 11*9 ------ 99

Best wishes

[tianzhu]

Trevortan:

2. A figure is made up of a rectangle and a square. The ratio of the area of the square to that of the rectangle is 2:5. If 1/4 of the square is shaded, what fraction of the figure is unshaded?

Hi

Is there a diagram provided in this question?

Square:Rectangle ------ 2:5 ------ 4:10

Fraction of figure@unshaded ------ 12/13

Best wishes

[tianzhu]

Trevortan:

1. A survey shows that the students of Chesvoire School come to school either by bus, MRT or by private transport. 2/5 of the students come to school by bus. The remaining students travel to school by MRT and private transport in the ratio 3:4. Given that 180 more students take the school bus than private transport, how many students are there in Chesvoire School?

Hi

Good Morning.

It helps to draw MD. You may also work using units.

Bus:MRT+Private transport ------ 2:3 ------ 14:21

MRT:Private Transport ------ 3:4 ------ 9:12

Bus ------ 14 units

MRT ------ 9 units

Private transport ------ 12 units

2 units ------- 180

1 unit ------- 90

Number of students ------- 35*90 -------- 3150

Best wishes

[doraemo]

oic…

Thank you MathIzzzFun & tianzhu !!!

[Jamesbond]

Grandma had some yellow and purple sweets in the ratio of 9:7. On Monday, she made 54 more yellow sweets. On Tuesday she gave away 44 purple sweets and sold 129 yellow sweets. The number of yellow sweets to the number of purple sweets became in the ratio of 6:5. How many yellow sweets are there in the end?

Pl help…

[Jamesbond]

tianzhu:

Jamesbond:

Using 3/5 of her money, Chloe could buy 11 notebooks. If she was given an extra $2, she could use it together with the remaining amount of money to buy another 8 such notebooks. How much money did Chloe have?

Hi

3 units ------ 11NB

2 units + 2 ------ 8NB

Make the number of NB equal

24 units ------- 88NB

22 units + 22 ------- 88NB

24 units ------- 22 units + 22

1 unit ------- 11

Chloe --------- 5*11 ------ 55

Best wishes

Thx Tianzhu

[tianzhu]

Jamesbond:

Grandma had some yellow and purple sweets in the ratio of 9:7. On Monday, she made 54 more yellow sweets. On Tuesday she gave away 44 purple sweets and sold 129 yellow sweets. The number of yellow sweets to the number of purple sweets became in the ratio of 6:5. How many yellow sweets are there in the end?

Pl help...

Hi

This question has been discussed before in this thread.

Hope this helps

Best wishes

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