Q&A - P5 Math

[Oracle]

Thank you Snowball & MathIzzzFun!

[Oracle]

Hi Math Gurus,


Please may I know how to solve this using the supposition method:
Kumaran had 64 coins in his coin box. There were 20-cent coins and 50-cent coins. The total value of all the coins was $18.50. How many 20-cent coins and how many 50-cent coins were there? Thank you very much.

[Oracle]

One more?


A sweet cost 15 cents and a packet of 8 similar sweets cost $1. Clement bought exactly 37 sweets. What was the least amount of money that Clement spent on the sweets?

[php]

Oracle:

One more?


A sweet cost 15 cents and a packet of 8 similar sweets cost $1. Clement bought exactly 37 sweets. What was the least amount of money that Clement spent on the sweets?

4 packets -> 4 x 8 = 32 sweets ($1 x 4 = $4)
5 sweets ($0.15 x 5 = $0.75)

Total spent : $4.75

[MathIzzzFun]

Oracle:

Hi Math Gurus,


Please may I know how to solve this using the supposition method:
Kumaran had 64 coins in his coin box. There were 20-cent coins and 50-cent coins. The total value of all the coins was $18.50. How many 20-cent coins and how many 50-cent coins were there? Thank you very much.

assume all are 50-cent coins --> 64 x $0.50 = $32
$32-$18.50 = $13.50 --> excess value assumed for 20-cent coins
Number of 20-cent coins = $13.50 /($0.50-$0.30) =45
number of 50-cent coins = 64 - 45 = 19

cheers.

[Oracle]

Thanks PHP. So the last 5 sweets that do not form a packet need to be accounted for individually i.e., 15 cents each.

[Oracle]

Here’s another:


During a mathematics test, Raymond scored 14 marks more than Krishnan and 7 marks more than Edison. Given that Raymond and Krishnan scored 73 marks more than Edison, what was Raymond’s score for the test?

[MathIzzzFun]

Oracle:

Here’s another:


During a mathematics test, Raymond scored 14 marks more than Krishnan and 7 marks more than Edison. Given that Raymond and Krishnan scored 73 marks more than Edison, what was Raymond’s score for the test?

Raymond scored 7 more than Edison
Raymond and Krishnan scored 73 more than Edison
so, Krisnan's score = 73-7=66
Raymond's score = 66 + 14 = 80
Edison's score = 80-7 =73


cheers.

[php]

Oracle:

Thanks PHP. So the last 5 sweets that do not form a packet need to be accounted for individually i.e., 15 cents each.

yes, because the question stated he bought 37 sweets exactly.

[Jamesbond]

tayobus:

There were twice as many red marbles as yellow marbles in a box.

When 2 red marbles were put into the box and 6 yellow marble were taken out, there was 3 times as many red marbles than yellow marble in the box.
What was the total number of marbles at 1st?
:?: :imdrowning: :thankyou:

6+2=8
8*4=32
32-2=30
30+6=36.