Q&A - PSLE Math

[pensiveowl]

Hi… Can someone pls help with this question - thanks!


Linda mixed 3 l of blue paint with 7 l of white paint. She then poured out 4 l of the mixture into a pail and added 6 l of red paint into the pail. Find the ratio of the volume of blue paint to the volume of red paint in the pail.

[raghupavithra]

thankyou

[raghupavithra]

four boys, Alex,Ben,carl and dan shared the cost of a present equally. carl had some money but he did not have enough to pay for his share.Alex paid more to makeup the difference for carl. the amount of money paid by alex is 1/2of the total amount paid by ben, carl and dan. the amount of money paid by ben is 1/3 of the amount paid alex,carl,and dan. the amount of money paid by carl is 1/5 of the total amount paid by alex,ben and dan.if carl returned $38 to alex the next day, find the cost of the present.


how to solve this

[raghupavithra]

In the toy shop, there were 32more dolls than toy cars. When 2/7 of the toy cars were sold, there were 80 toy cars fewer than dolls.


a] How many dolls were in the shop at first?

b] What fraction of dolls must be sold so that there would be the same number of dolls as toy cars left now? (Give your answer in its simplest form)

how to solve this sum

[jieheng]

raghupavithra:

four boys, Alex,Ben,carl and dan shared the cost of a present equally. carl had some money but he did not have enough to pay for his share.Alex paid more to makeup the difference for carl. the amount of money paid by alex is 1/2of the total amount paid by ben, carl and dan. the amount of money paid by ben is 1/3 of the amount paid alex,carl,and dan. the amount of money paid by carl is 1/5 of the total amount paid by alex,ben and dan.if carl returned $38 to alex the next day, find the cost of the present.


how to solve this

the amount of money paid by carl is 1/5 of the total amount paid by alex,ben and dan
Carl paid []
total amount paid by Alex , Ben and Dan [][][][][]

Carl paid 1/6 of the total cost

Carl should pay 1/4 of the total cost as four boys shared the cost of a present equally

the amount that Alex paid more to makeup the difference for carl = 1/4 - 1/6 = 1/12

1u --> 38
12u --> 38*12 = 456

the cost of the present is $456 (Ans)

[jieheng]

raghupavithra:

In the toy shop, there were 32more dolls than toy cars. When 2/7 of the toy cars were sold, there were 80 toy cars fewer than dolls.


a] How many dolls were in the shop at first?

b] What fraction of dolls must be sold so that there would be the same number of dolls as toy cars left now? (Give your answer in its simplest form)

how to solve this sum

a)

D [][][][][][][][32]
C [][][][][][][]

When 2/7 of the toy cars were sold, there were 80 toy cars fewer than dolls.

D [][][][][][][][32]
C [][][][][]

2u + 32 --> 80
2u --> 80 - 32 = 48
1u --> 24

At first , no. of dolls were in the shop = 7u + 32 = 7*24 + 32 = 200 (Ans)

b)

5u --> 5*24 = 120

the fraction of dolls must be sold = (200-120)/200 = 80/200 = 2/5 (Ans)

[raghupavithra]

thanks

[jieheng]

pensiveowl:

Hi.. Can someone pls help with this question - thanks!


Linda mixed 3 l of blue paint with 7 l of white paint. She then poured out 4 l of the mixture into a pail and added 6 l of red paint into the pail. Find the ratio of the volume of blue paint to the volume of red paint in the pail.

Volume of blue paint in 4 l of mixture = 3/(3+7) * 4 = 3/10 * 4 = 1.2

the ratio of the volume of blue paint to the volume of red paint in the pail = 1.2 : 6 = 12 : 60 = 1 : 5 (Ans)

[jieheng]

raghupavithra:

thanks

You are welcome .

Regards,

[pensiveowl]

Thanks jieheng