Tutor MathsGuru: Ask me for your burning Maths questions!

[MathIzzzFun]

concern_mum:

hi, can you show me in detail how to solve below question?


The ratio of Atrirah's monety to Malek's money was 3:5
After Malek spent $42, the ratio of Atirah's money to Malek's money became 9:8
How much money did Malek have left?

Hi

Only Malek spent money, so Atrirah's money will remain the same. So, make Atrirah's share the same - drawing a model will help to \"see\".

After Malek spent $42, Atrirah : Malek = 9u : 8u
Before Malek spent the money, Atrirah : Malek = 3: 5 = 9u:15u
So, Malek spent 15u-8u=7u = $42, 1u = $6.
Malek had 15u left --> 15 x $ 6 = $90.

cheers.

[MathIzzzFun]

concern_mum:

hi, 1 more question i need help.


There are twice as many 20 cent coin as 50 cents coins in a piggy bank. The total value of the coins is $63. How manu coins are there altogether.

Hi

There are twice as many 20 cents coin as 50 cents.
Group 2x 20c and 1x50c into one group.
Total amount in each group = 2x$0.20 + $0.50 = $0.90
$63/ $0.90 = 70 --> there are 70 groups.

Since there 3 coins (2 x 20c + 1x50c) in each group, total number of coins = 70 x 3 = 210

cheers.

[concern_mum]

hi, i have another 2 questions that need your help.


1. 608 children took part in a skipping competition. Altogether 110 Gold awards were presented to 1/5 of the boys and 1/7 of the grils. How many boys took part in the competition.

2. The ratio of Steven’s cards to Benny’s cards was 3:4. After Steven bought another 9 cards and Benny lost 18 cards, the ratio became 3:2. Find the total number of cards Steven and Benny had at first.

Thank you.

[Essential]

Dear concern mum some one posted this before. Please check

[concern_mum]

Hi, sorry to bother you. I couldn’t find this posted. Could you advise me when was the date it was posted?

[Essential]

I suppose is page 380.

[concern_mum]

hi, i search from page 370 till 390 and still couldn’t find the solution.

[MathIzzzFun]

concern_mum:

hi, i have another 2 questions that need your help.


1. 608 children took part in a skipping competition. Altogether 110 Gold awards were presented to 1/5 of the boys and 1/7 of the grils. How many boys took part in the competition.

2. The ratio of Steven's cards to Benny's cards was 3:4. After Steven bought another 9 cards and Benny lost 18 cards, the ratio became 3:2. Find the total number of cards Steven and Benny had at first.

Thank you.

Hi

q2 is similar to the one you posted earlier - \"Atrirah & Malek\".

Initially, Steven's cards : Benny's cards = 3u : 4u
After Steven bought 9 cards --> Steven's cards = 3u + 9
Benny lost 18 cards --> Benny's cards = 4u - 18
3u+9 : 4u-18 = 3:2

Cross-multiply --> 6u + 18 = 12u - 54, 6u = 72, 1u = 12 .. I think you can carry on from here.

q1 can be solved using the \"stars & moons\" method the students learned in P1-P3.

Girls = * * * * * * * } 608
Boys = # # # # # }

* + # = 110,
so * * = 608 - 5 x 110 = 58,
* = 29
# = 110 - 29 = 81

Boys = 5 # = 405

cheers.

[concern_mum]

hi Guru, thank you for your clear explanation. Q1 seems to be a problem. I have a feeling that the information is insufficient for this question.

[MathIzzzFun]

concern_mum:

hi Guru, thank you for your clear explanation. Q1 seems to be a problem. I have a feeling that the information is insufficient for this question.

Hi

u r welcome.. I am no guru la.. just trying to help out here.

q1 type of problem sums are quite common. for eg.

http://www.flickr.com/photos/62167097@N02/6160671185/in/photostream

http://www.flickr.com/photos/62167097@N02/6175230767/in/photostream

cheers.