Q&A - P5 Math
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redruby:
Dan and Tan shared a number of balls in the ratio 4:5. After Dan and Tan purchased another 13 balls and 5 balls respectively, the ratio became 5:4. How many balls did Dan have at first?
Hi
Before
Dan:Tan ------4u:5u
Changes
Dan:Tan ------ 13:5
After
Dan:Tan ------5p:4p
Make the parts the same.
4u + 13 ------ 5p
(x4)
16u + 52 ------ 20p
5u + 5 ------- 4p
(x5)
25u + 25 ------- 20p
16u + 52 ------- 25u + 25
9u ------- 27
1u ------- 3
Dan@first ------- 4*3 --------12
For more questions to practise, please follow this link.
http://www.kiasuparents.com/kiasu/content/math-questions-involving-changed-quantities
Best wishes -
Can tianzhu help me in the questions?
1/3 of the amount of money Oliver has is the same as 2/3 of the amount of money Kayla has.
a) If Oliver has $60 more than Kayla, how much money does Oliver have?
b) If Oliver has $120 more than Kayla, how much money does Oliver have than Kayla?
Kamal bought 143 red markers and black markers. After he gave the same number of red markers and black markers, he was left with 3/7 of the red markers and 1/3 of the black markers. How many black markers did he have left?
Thanks in advance! -
tianzhu:
Thx.redruby:
Dan and Tan shared a number of balls in the ratio 4:5. After Dan and Tan purchased another 13 balls and 5 balls respectively, the ratio became 5:4. How many balls did Dan have at first?
Hi
Before
Dan:Tan ------4u:5u
Changes
Dan:Tan ------ 13:5
After
Dan:Tan ------5p:4p
Make the parts the same.
4u + 13 ------ 5p
(x4)
16u + 52 ------ 20p
5u + 5 ------- 4p
(x5)
25u + 25 ------- 20p
16u + 52 ------- 25u + 25
9u ------- 27
1u ------- 3
Dan@first ------- 4*3 --------12
For more questions to practise, please follow this link.
http://www.kiasuparents.com/kiasu/content/math-questions-involving-changed-quantities
Best wishes -
Tina earned $600 more than Bala every month. Both of them spent $2400 each month and saved the rest. When Tina saved $9000, Bala saved only $4800. How much did Tina spend in total?
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The Nos of chicken eggs is 40 more than 5 times that of duck eggs, the Nos of crocodile eggs is 4 more than 1/10 of chicken eggs. There are 6 fewer crocodile eggs than duck eggs. How many eggs are there?
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hi
pls help, this is 2mark qns, but my method is kind of long winded, wanted to know if there is shorter method
For every 2packets of sugar bought at $1.4 each, a third packet may be purchased at a special price. Lenny bought 15 packets of sugar and save a total of $3. what was the special price for the third packet. -
pls help
1)the ratio of the number of apples to the number of oranges in box A is 4:1 while that in Box B is 3:2. Box A has thrice as many fruits as box b. When 14 oranges are transferred from box a to box b, the number of oranges in box a is 7/8 of the number of oranges in box B. find the number of apples in box A at first -
redruby:
Tina earned $600 more than Bala every month. Both of them spent $2400 each month and saved the rest. When Tina saved $9000, Bala saved only $4800. How much did Tina spend in total?
Since both spent the same amount, the saving difference will be due to their difference in earnings. Each month, Tina earned $600 more. So it will take
$9000-$4800=$4200
$4200 / $600 = 7 months to get the stated amount saved.
Ans: 7 X $2400 = $16800
Cheers. -
carol73:
Since box A has thrice as box B, total units of A should be thrice as well.pls help
1)the ratio of the number of apples to the number of oranges in box A is 4:1 while that in Box B is 3:2. Box A has thrice as many fruits as box b. When 14 oranges are transferred from box a to box b, the number of oranges in box a is 7/8 of the number of oranges in box B. find the number of apples in box A at first
So APP in A : ORA in A : APP in B : ORA in B = 12 : 3 : 3 : 2
Now lets consider Oranges.
Before:
A:B is 3:2.
After:
A:B is 7:8.
Since the total oranges remains the same, we should make total units before and after the same.
Before:
A:B is 9:6.
After:
A:B is 7:8.
So 2 units --> 14 was transferred.
9 units --> 7 X 9 = 63.
There were 63 oranges in A at first.
Thus, there were 63 X 4 = 252 apples in A at first.
Cheers. -
carol73:
We group the sugars into 3-packet groups - 2 packets at $1.40 each and 1 packet at special price.hi
pls help, this is 2mark qns, but my method is kind of long winded, wanted to know if there is shorter method
For every 2packets of sugar bought at $1.4 each, a third packet may be purchased at a special price. Lenny bought 15 packets of sugar and save a total of $3. what was the special price for the third packet.
In 15 packets, there will be 15/3=5 groups.
5 groups will mean there will be 5 packets with special price.
A total of $3 was saved for 5 packets with special price, meaning $3/5=$0.60 was saved per packet.
Special Price -->$1.40-$0.60=$0.80
Cheers.