Tutor MathsGuru: Ask me for your burning Maths questions!

[Herbie]

Hi I have one question


Paul and Ray worked together to paint a house. During the job Paul rested for 4 days and Ray took 2 days off. However, they were not absent on the same days. If they had done the same job alone. Paul would have taken 18 days and Ray 12 days.

How long did the two painters take to complete painting the house?

Kindly assist.

My working.
Work done by Paul in one day = 1/18
Work done by Ray in one day = 1/12

Work done for one house in one day = 1/18 + 1/12 = 5/36

Portion of work left = 1-5/36 = 31/36

Then 31/5 = 6.2 = 6.5 days

No. of days required to complete the work = 6.5 + 2 + 4 = 12.5 days

Is my answer correct???

Tx

[Dharma]

Herbie:

Hi I have one question


Paul and Ray worked together to paint a house. During the job Paul rested for 4 days and Ray took 2 days off. However, they were not absent on the same days. If they had done the same job alone. Paul would have taken 18 days and Ray 12 days.

How long did the two painters take to complete painting the house?

Kindly assist.

My working.
Work done by Paul in one day = 1/18
Work done by Ray in one day = 1/12

Work done for one house in one day = 1/18 + 1/12 = 5/36

Portion of work left = 1-5/36 = 31/36

Then 31/5 = 6.2 = 6.5 days

No. of days required to complete the work = 6.5 + 2 + 4 = 12.5 days

Is my answer correct???

Tx

Paul – 1 day => 1/18 of job
Ray – 1 day => 1/12 of job
Paul & Ray – 1 day => 1/18 + 1/12 = 30/(18x 12) = 5/36 of job

Let say Paul and Ray take N days to complete job

Paul => N days to complete => (N – 4)/18 of job
Ray = > N days to complete => (N – 2)/ 12 of job

N/18 – 4/18 + N/12 – 2/12 = 1
5N/36 – 7/18 = 1
(5N – 14)/36 = 36/36
5N – 14 = 36
5N = 50
N = 10 days

[DragonAxe]

Herbie:

Hi I have one question


Paul and Ray worked together to paint a house. During the job Paul rested for 4 days and Ray took 2 days off. However, they were not absent on the same days. If they had done the same job alone. Paul would have taken 18 days and Ray 12 days.

How long did the two painters take to complete painting the house?

Paul - 1/18 / day
Ray - 1/12 / day


During Paul's off day :
Ray did 4/12 of the job


During Ray's off day :
2/18

1/18+1/12 = 2/36 + 3/36 = 5/36

1 - 4/12 - 2/18
= 8/12 - 2/18
= 24/36 - 4/36
= 20/36

20/36 divide by 5/36 = 4

4 days + 4 days + 2 days = 10 days.

[DragonAxe]

hapie_always:

Hi Mathsguru,


I have a math problem. Hope you can help me with it.

3 boys shared a box of oranges. Ted took 1/3 and 6 of the oranges. Bob took 1/2 of the remainder and 9 of the oranges. Ken took the last remaining 5 oranges. How many oranges were in the box at first?

Thanks in advance!

5+9=14
14*2=28
28+6=34
3/2 * 34 = 51

CHECK
Ted - 17+6= 23 | 28 left
Bob - 14+9= 23 | 5 left
Ken - 5 oranges.

[Ngserene617]

mathsguru:

Original Title: Let MathsGuru Answer Your Burning Maths Questions!


:welcome:

Dear Parents,

Are you frustrated/stuck when helping your child solve his/her Maths questions? Are you inclined to use Algebra most of the time? Do you have difficulty trying to use diagrams or other heuristic methods (that Primary School students learn) to solve?

:idea: Post your questions here and see how MathsGuru solve them to the best of her ability. Detailed solutions will be posted back in this thread.


Hi can someone help me to solve this question:
- Find the value of 60 divide 80 divide 5 x 4
thanks !


So start asking and watch this space!!

Cheers :celebrate: ,
MathsGuru

P/S (Disclaimer, in case you're wondering...):
Although MathsGuru is a full-time Maths tutor, this thread is meant to be an absolutely free resource for parents (or even children) with no strings attached. Just someone who's passionate about Maths and wanna spread the fun in learning Maths with others.

[Ngserene617]

Hi can someone help me to solve this question:

- Find the value of 60 divide 80 divide 5 x 4
thanks !

mathsguru:

Original Title: Let MathsGuru Answer Your Burning Maths Questions!

:welcome:

Dear Parents,

Are you frustrated/stuck when helping your child solve his/her Maths questions? Are you inclined to use Algebra most of the time? Do you have difficulty trying to use diagrams or other heuristic methods (that Primary School students learn) to solve?

:idea: Post your questions here and see how MathsGuru solve them to the best of her ability. Detailed solutions will be posted back in this thread.

So start asking and watch this space!!

Cheers :celebrate: ,
MathsGuru

P/S (Disclaimer, in case you're wondering...):
Although MathsGuru is a full-time Maths tutor, this thread is meant to be an absolutely free resource for parents (or even children) with no strings attached. Just someone who's passionate about Maths and wanna spread the fun in learning Maths with others.

[Dharma]

Ngserene617:

Hi can someone help me to solve this question:

- Find the value of 60 divide 80 divide 5 x 4
thanks !

60/80/5 x 4
= 3/4/5 x 4
=3/5

[kancheongmum]

hi all


appreciate your help in the problem P6 Hokkien HK prelim Q15

A car and a coach travelled from Town A to Town B. The coach left Town A at 0648 and it took 5 hrs to reach Town B. The car started 30 mins later than the coach and it took 4 hrs to reach Town B. At what time did the car catch up with the coach? (ans 0918)

I saw the solution somewhere but don’t understand so can’t explain to my DS.

Thanks

[Muffins]

kancheongmum:

hi all


appreciate your help in the problem P6 Hokkien HK prelim Q15

A car and a coach travelled from Town A to Town B. The coach left Town A at 0648 and it took 5 hrs to reach Town B. The car started 30 mins later than the coach and it took 4 hrs to reach Town B. At what time did the car catch up with the coach? (ans 0918)

I saw the solution somewhere but don't understand so can't explain to my DS.

Thanks

Time taken (Coach) : Time taken (Car) -> 5 : 4
Time difference -> 1u -> 30 min = 1/2 hr

Time (car) -> 4u -> 4x 1/2hr = 2hr

the car passed 2 hrs later

06 48 + 30 min + 2 hr -> 09 18

[kancheongmum]

hi muffins

tks for the solution understand now