piang. like that also can. gum sia leh.ChiefKiasu wrote: It's also a test of your Harry Potter knowledge. The correct spelling for the unforgivable spell is CRUCIO, ie. 6 letters.
So total number of letters in the 4 spells = 26.
Total number of letters in the 6 spells = 9x6 =54
So total number of letters in the remaining 2 spells = 54-26 = 28
So each remaining spell has 28/2 = 14 letters each
Q&A - PSLE Math
P5 Math
[Moderator's note: Topics merged.]
Can anyone help?
Q1. Bobby, Edward and kelvin made a bottle of paper stars. The number of paper stars Bobby made was 21 more than 1/4 the total number of paper stars int he bottle. The num,ber of paper stars Edward made was 30 more than 1/4 of the remaining number of paper stars in the bottle. Kelvin made the remaining 114 paper stars. How many paper stars did they make in all?
Q2. A, B and C are three numbers. The average a, B and C is 5 greater tha the averaga of A and b. If C is 38, find the total of A, B and C.
Thank you.
Can anyone help?
Q1. Bobby, Edward and kelvin made a bottle of paper stars. The number of paper stars Bobby made was 21 more than 1/4 the total number of paper stars int he bottle. The num,ber of paper stars Edward made was 30 more than 1/4 of the remaining number of paper stars in the bottle. Kelvin made the remaining 114 paper stars. How many paper stars did they make in all?
Q2. A, B and C are three numbers. The average a, B and C is 5 greater tha the averaga of A and b. If C is 38, find the total of A, B and C.
Thank you.
lizawa - i stil don't understand still leh. So sorry. Got easier explanation?
How to do this?
May earned twice as much money as her brother. After May spent $32 and her brother spent $50, the ratio of money May had left to the amount of money her brother had left was 7:3. Find the amount of money May earned.
Thanks.
How to do this?
May earned twice as much money as her brother. After May spent $32 and her brother spent $50, the ratio of money May had left to the amount of money her brother had left was 7:3. Find the amount of money May earned.
Thanks.
youngmum, solution for new question as follows:
May ____________________________ ____________________________
May {---------32-------}{----------------------7 units-----------------------------------}
Bro ____________________________
Bro {------50-------------}{----3units----}
So the equation is:
32 + 7 units = 2(50 + 3 units)
32 + 7 units = 100 + 6 units
1 unit = 100-32 = 68
Hence May earned 7(68 )+32 = $508
May ____________________________ ____________________________
May {---------32-------}{----------------------7 units-----------------------------------}
Bro ____________________________
Bro {------50-------------}{----3units----}
So the equation is:
32 + 7 units = 2(50 + 3 units)
32 + 7 units = 100 + 6 units
1 unit = 100-32 = 68
Hence May earned 7(68 )+32 = $508
The other question is changing % into fractions that lizawa has cleverly done as it is easier to think in 1 unit than as 20% or 25%.
20% = 1 in 5 parts
25% = 1 in 4 parts
it is known total people = 1150
total non-photographers = 250
20% men and 25% women = 250 so in fraction:
1 unit of men + 1 unit of women = 250
since 1 unit of men and 1 unit of women are different things, it is hard to make comparison, however, we know that if we take away 4 units from men and women, the remainder is 1 unit of men.
hence 250*4 = 1000
1150-1000 = 150
Only then you will know 1 unit of men(=20% of men) = 150
so total men(100% of men) = 150*5 = 750
1 unit of women(=25% of women) = 250-150 = 100
so total women (100% of women) = 100*4 = 400
hence difference between men and women = 750-400=350
20% = 1 in 5 parts
25% = 1 in 4 parts
it is known total people = 1150
total non-photographers = 250
20% men and 25% women = 250 so in fraction:
1 unit of men + 1 unit of women = 250
since 1 unit of men and 1 unit of women are different things, it is hard to make comparison, however, we know that if we take away 4 units from men and women, the remainder is 1 unit of men.
hence 250*4 = 1000
1150-1000 = 150
Only then you will know 1 unit of men(=20% of men) = 150
so total men(100% of men) = 150*5 = 750
1 unit of women(=25% of women) = 250-150 = 100
so total women (100% of women) = 100*4 = 400
hence difference between men and women = 750-400=350
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Re: P5 Math
Start backwards from Edward. Since Edward made 30 more than a quarter of the stars and Kelvin made the rest, it means that Kelvin's stars plus 30 makes up 3/4 of the stars,Sarah wrote:...Q1. Bobby, Edward and kelvin made a bottle of paper stars. The number of paper stars Bobby made was 21 more than 1/4 the total number of paper stars in the bottle. The number of paper stars Edward made was 30 more than 1/4 of the remaining number of paper stars in the bottle. Kelvin made the remaining 114 paper stars. How many paper stars did they make in all?
ie. 114 + 30 = 144 is 3/4 of the stars
So the sum of Edward's and Kelvin's stars is 144 x 4/3 = 192
We apply the same principle with Bobby's stars now.
3/4 of the total stars = 192 + 21 = 213
So the total number of stars made by all 3 children is 213 x 4/3 = 284
(A+B+C)/3 = (A+B)/2 + 5Sarah wrote:...Q2. A, B and C are three numbers. The average of A, B and C is 5 greater than the average of A and B. If C is 38, find the total of A, B and C...
A+B+C = 3(A+B)/2 + 15
A+B+38 = 3(A+B)/2 + 15
A+B+23 = 3(A+B)/2
2(A+B)+46 = 3(A+B)
=> A+B = 46
=> A+B+C = 46 + 38 = 84