Q&A - P5 Math

[tianzhu]

S-H:

tianzhu:

Thank you tianzhu, but I still don't understand why one wrong answer is 8 marks and not 3 marks which was stated in the question??

Hi S-H

Right answer ----- plus 5 marks

Wrong answer ----- minus 3 marks

Difference between a right and wrong answer ------ 8 marks

Best wishes

[Augmum]

S-H:

tianzhu:

[quote=\"S-H\"]Hi, can someone please help me with this question, thank you!


There are 30 questions in a mathematics competition. 5 marks are awarded for each question answered correctly. 3 marks are deducted for each wrong answer. Ben scored 118 marks for this competition. How many questions did he get wrong?

Hi S-H

You may use “Make a Supposition/Assumption concept”

If Ben got all his answers correct, he would get (30*5) or 150 marks.

150 – 118 ----- 32

One wrong answer costs (5 + 3) or 8 marks

Number of wrong answers ------- 32/8 ------- 4

Best wishes

Thank you tianzhu, but I still don't understand why one wrong answer is 8 marks and not 3 marks which was stated in the question??[/quote]Happenonline to see yr question, juz chip in to help Tianzhu....

Becos for each wrong answer, u not only not awarded the 5 marks , plus 3 marks being deducted,
so a total loss of 8 marks.....

[Augmum]

Oops...S-H....tianzhu already answered yr question....while i was typing....

[S-H]

Augmum:

Oops...S-H....tianzhu already answered yr question....while i was typing....

Thank you Augmum and tianzhu, I understand now

[S-H]

Hi, there is another question I need someone to help, thanks.


The ratio of the number of staplers to the number of rulers in a bookshop was 3:4. Each stapler cost $3. Each ruler cost $1. The shopkeeper would be able to collect a total of $5850 from the sale of all her staplers and rulers.
(a) How many rulers were there?
(b) How many staplers were there?

[tianzhu]

S-H:

Hi, there is another question I need someone to help, thanks.


The ratio of the number of staplers to the number of rulers in a bookshop was 3:4. Each stapler cost $3. Each ruler cost $1. The shopkeeper would be able to collect a total of $5850 from the sale of all her staplers and rulers.
(a) How many rulers were there?
(b) How many staplers were there?

Hi

Good Morning.

You may use the “Grouping concept”

Consider a group or set of 3 staplers and 4 rulers.

(3*3) + (4*1) ----- 13

5850/13 ----- 450

There are 450 groups.

Number of staplers ------- 450*3 ------ 1350

Number of rulers ------- 450*4 ------ 1800

Hope this helps.

Best wishes

[tianzhu]

S-H:

Hi, there is another question I need someone to help, thanks.


The ratio of the number of staplers to the number of rulers in a bookshop was 3:4. Each stapler cost $3. Each ruler cost $1. The shopkeeper would be able to collect a total of $5850 from the sale of all her staplers and rulers.
(a) How many rulers were there?
(b) How many staplers were there?

Hi

You may also present your solution using the \" Number*Value\" approach.

Hope this helps.

Best wishes.

http://farm8.staticflickr.com/7414/8797974227_0aa4b3cd62_z.jpg\">

[S-H]

tianzhu:

S-H:

Hi, there is another question I need someone to help, thanks.


The ratio of the number of staplers to the number of rulers in a bookshop was 3:4. Each stapler cost $3. Each ruler cost $1. The shopkeeper would be able to collect a total of $5850 from the sale of all her staplers and rulers.
(a) How many rulers were there?
(b) How many staplers were there?

Hi

You may also present your solution using the \" Number*Value\" approach.

Hope this helps.

Best wishes.u

http://farm8.staticflickr.com/7414/8797974227_0aa4b3cd62_z.jpg\">

Hi, why you multiply the ratio and the unit price together, as what I know, the ratio is not the actual number of the items. Pls kindly explain, thanks.

[pup_love_Claire]

Hi S-H,


the ratio and unit price are multiply together to create the total price for 1 SET of the mentioned items e.g 3 staples and 4 rulers. The ratio sort of give you the items to make a group or set. From there, we can calculate how many group/set are there in the given total amount.

Hope it helps.

[Jamesbond]

At Tans fruit stall, 3/4 of the apples were red and the rest were green. He sold 1/2 of the total number of apples. 5/6 of the apples sold were red. 28 green apples were left. How many red apples did Tan sell?