Need help on the reasoning for the following ratios problem
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Need help on the reasoning for the following ratios problem
Hi
Stuck on the following, and just need help on a method more than an answer:
David's savings is four times that of Peter. When he spends £15 and Peter saves £45, both of them have the same amount of money. How much does each of them have in their savings at first?
Stuck on the following, and just need help on a method more than an answer:
David's savings is four times that of Peter. When he spends £15 and Peter saves £45, both of them have the same amount of money. How much does each of them have in their savings at first?
Re: Need help on the reasoning for the following ratios prob
Well I said that if one spends £15 and the other saves £45 and they end up the same then this changes their difference by £60.
Difference = 3 lots of what Peter has (one has 4 times as much as the other)
so Peter must have £20.
Test:
David £80, Peter £20
then David £80 - £15 = £65
Peter £20 + £45 = £65
Difference = 3 lots of what Peter has (one has 4 times as much as the other)
so Peter must have £20.
Test:
David £80, Peter £20
then David £80 - £15 = £65
Peter £20 + £45 = £65
Re: Need help on the reasoning for the following ratios prob
Thanks Guest55
The answers showed:
3 units = £45 + £15 = £60
1 unit = £60 / 3 = £20
4 units = £20 X 4 = £80
David has £80 and Peter has £20 - both at first.
I prefer your (Guest55) explanation.
The answers showed:
3 units = £45 + £15 = £60
1 unit = £60 / 3 = £20
4 units = £20 X 4 = £80
David has £80 and Peter has £20 - both at first.
I prefer your (Guest55) explanation.
Re: Need help on the reasoning for the following ratios prob
Thanks! You are welcome ...
Re: Need help on the reasoning for the following ratios prob
The worrying thing is that it is a Year 4 question!Guest55 wrote:Thanks! You are welcome ...
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Re: Need help on the reasoning for the following ratios prob
David's savings is four times that of Peter. When he spends £15 and Peter saves £45, both of them have the same amount of money. How much does each of them have in their savings at first?
Hi.. Would have done..
4a -15 =a + 45
So 3a =60
And a = 60/3
Very surprised it is a yr 4 question, please may I ask what source it's from?
Thanks
Sleepyhead
Hi.. Would have done..
4a -15 =a + 45
So 3a =60
And a = 60/3
Very surprised it is a yr 4 question, please may I ask what source it's from?
Thanks
Sleepyhead
Re: Need help on the reasoning for the following ratios prob
No need to use algebra - you should really avoid it until it's abolutely necessary.
Re: Need help on the reasoning for the following ratios prob
Not sure I agree with that - the Durham CEM test often contains algebra questions in the Maths section so better that they get used to putting this practiceNo need to use algebra - you should really avoid it until it's abolutely necessary.
Need help on the following question.
Need help on the workings for the following question, please.
It takes 5 minutes to fry a beef burger. One side of the beef burger takes 3 minutes to fry and the other side takes only 2 minutes. Two beef burgers can be placed on the frying pan at a time. What is the shortest time to fry all five beef burgers?
The answer is not 15 mins, it is 13 minutes.
It takes 5 minutes to fry a beef burger. One side of the beef burger takes 3 minutes to fry and the other side takes only 2 minutes. Two beef burgers can be placed on the frying pan at a time. What is the shortest time to fry all five beef burgers?
The answer is not 15 mins, it is 13 minutes.
Re: Need help on the following question.
Code: Select all
minute | left side of pan | right side of pan
1 | A1 | B1
2 | A1 | B1
3 | A1 | B1
4 | C1 | B2
5 | C1 | B2
6 | C1 | E1
7 | C2 | E1
8 | C2 | E1
9 | D1 | E2
10 | D1 | E2
11 | D1 | A2
12 | D2 | A2
13 | D2 |