Q&A - PSLE Math

[tianzhu]

Michaelia0816:

Hey, I not sure,pls help pls

Hi girl

Please post the picture of the prism.

Best wishes

[Michaelia0816]

Never mind, it just a picture of a triangle prism

[Michaelia0816]

Pls help, I really don't know, pls also help with the other 11 questions. :?:


1. 10 workers can complete a painting job. If there are 2 more workers, the painting job will be completed 6 days sooner. If the same painting job were to be done 21 days earlier, how many additional workers are needed?

[Michaelia0816]

2. 173 sweets are to be given to 8 kids in as fair manner as possible. What is the maximum number of sweets a kid can get?

[Michaelia0816]

3. 2 candles of the equal length are lit at the same time. One candle took 5 hours to burn out and the other 2.5 hour. After how long will the length of the faster burning candle be 4/7 of the slower burning one?

[Michaelia0816]

4. 2 groups of people , A and B are working on a project. If 18 people move from group A to group B, then group B will have 3 more people than group A. If we take away 18 people from both groups, then the remaining people in group B is 5/8 of that of group A. Find the number of people in each group at first.

[match3frog]

Please help with this question. Thanks!



Adrian, Ben and Calvin share 436 marbles. After Adrian gave away 2/5 of his marbles, the ratio of the number of marbles he has to Ben became 4 : 9. When Calvin lost 1/3 of his marbles, the total number of marbles the children has was 352. How many marbles did Calvin have at first?

[Michaelia0816]

Pls help with my pervious 4 questions! On page 673

[MathIzzzFun]

match3frog:

Please help with this question. Thanks!



Adrian, Ben and Calvin share 436 marbles. After Adrian gave away 2/5 of his marbles, the ratio of the number of marbles he has to Ben became 4 : 9. When Calvin lost 1/3 of his marbles, the total number of marbles the children has was 352. How many marbles did Calvin have at first?

Hi

this is similar to the question which was posted @ http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=6690
\"A large warehouse had a total of 2180 black, red and white T-shirts for sale. The ratio of the number of black T-shirts to the number of red T-shirts was 3:1. After 2/5 of the black T-shirts, 1/3 of the white T-shirts and none of the red T-shirts were sold on the first day, there were 1504 T-shirts left. How many red T-shirts did the warehouse have at first?\"

Calvin's marbles --> 3p
After Adrian gave away 2/5 of his marbles,
Adrian's marbles : Ben's marbles = 4:9 = 12u (3/5 of Adrian's marbles) : 27u
At first,
Adrian's marbles : Ben's marbles : Calvin's marbles = 20u : 27u : 3p
--> 47u + 3p = 436 -- (1)

Number of marbles given away & lost
--> 8u + 1p = 436 - 352 = 84
--> 24u + 3p = 252 --(2)

(1) -- 47u + 3p = 436
(2) -- 24u + 3p = 252
23u --> 184, 1u --> 8

At first, Calvin's marbles --> 436 - 47 x 8 = 60

cheers.

[match3frog]

Thank you for the clear solution, mathizzzfun! Will attempt the other question too