BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

work problems

Expert replies
by taichka123 » Fri Oct 17, 2008 8:31 pm
Please help me with these two problems


1)
A and B can complete stitching in 6 hours, B and C can do the same in 8 hours, while C and A can complete it in 12 hours. How long would each of them take, doing the same work, separately?

A) A=48, B=9.6, C=16
B) 9.6, 48, 16
C) 16, 9.6, 48
D) 16, 48, 9.6



2) 1/4 of a work is completed by 8 persons in 12 days. Find the number of persons required to complete the remaining work in 16 days.

A)2
B)3
C)4
D)1



Thank you!
Join the discussion
Source: — Problem Solving |

by 2009wish » Fri Oct 17, 2008 10:08 pm
1.

work done by A+B in one day will be 1/ 6. similarly it will be 1/ 8 and 1/ 12 for B+C & C+A.

Adiing the above equation we get.........

2( A+B+C) =1 /6 +1/ 8+ 1/ 12

so work done by A+B+C in one day will be =3/ 16

3/ 16 -1/6 =work done by C in one day ie......48 ; A is 16

C is the answer
Join the discussion

Re: work problems

by Morgoth » Fri Oct 17, 2008 10:28 pm
taichka123 wrote:
2) 1/4 of a work is completed by 8 persons in 12 days. Find the number of persons required to complete the remaining work in 16 days.

A)2
B)3
C)4
D)1
Are you sure about the answer choices.

if 8 people finish 1/4 job in 12 days, you would definitely need more than 8 to finish the remaining job i.e 3/4 in 16 days.

Let me know if I am missing something.

I am getting 18 as the answer.
Join the discussion

by cramya » Fri Oct 17, 2008 10:30 pm
1) I get C) as the answer

Rate*time*no of machines = work

Let R1 be A's rate,R2 be B's rate and R3 be C's rate

(R1+R2)*6*1 = 1 => R1 = 1/6 - R2 (1)

(R2+R3) *8*1 = 1 =>R3 = 1/8 - R2 (2)

(R3+R1)*12*1 = 1 (3)

Substituting (1) and (2) in (3)

(1/8-R2+1/6-R2)*12*1 = 1

R2 = 5/48 SO T2 = 48/5 = 9.6

Substitute R2' values in (1) and (2)
R1=16
R3=48
Join the discussion

by cramya » Fri Oct 17, 2008 10:33 pm
For (2)

I did

1/4*8*12 = 3/4*x*16

x= 2

Morgoth, thougts?
Join the discussion

by Morgoth » Fri Oct 17, 2008 11:27 pm
cramya wrote:For (2)

I did

1/4*8*12 = 3/4*x*16

x= 2

Morgoth, thougts?
I am not sure about what you did.

Here is how I am getting 18

people * rate * time = work

8 * rate * 12 = 1/4

rate = 1/( 4*8*12)

people * rate * time = work

people * 1/( 4*8*12) * 16 = 3/4

people = 3/4 * ( 4*8*12)/16 = 18.


Alternatively, look at it in this way

let total work be 80

8 workers complete 20 out of 80 work in 12 hours.

do you think 2 workers can complete remaining 60 out of 80 in just 16 hours.

Let me know your thoughts.

Thanks.
Join the discussion

by 2009wish » Fri Oct 17, 2008 11:34 pm
agree with morgoth ------- work is directly proportional to men , days keeping the other constant.
Join the discussion

by raunekk » Sat Oct 18, 2008 1:25 am
@cramya

i think d question shud b..
2)
1/4 of a work is completed by 8 persons in 12 days. Find the number of additional persons required to complete the remaining work in 16 days.
Join the discussion

by 4meonly » Sat Oct 18, 2008 3:13 am
cramya wrote:1) I get C) as the answer

Rate*time*no of machines = work

Let R1 be A's rate,R2 be B's rate and R3 be C's rate

(R1+R2)*6*1 = 1 => R1 = 1/6 - R2 (1)

(R2+R3) *8*1 = 1 =>R3 = 1/8 - R2 (2)

(R3+R1)*12*1 = 1 (3)

Substituting (1) and (2) in (3)

(1/8-R2+1/6-R2)*12*1 = 1

R2 = 5/48 SO T2 = 48/5 = 9.6

Substitute R2' values in (1) and (2)
R1=16
R3=48
Super!

I had another approach:
What can be cocnluded from the main statement?
A and B can complete stitching in 6 hours, B and C can do the same in 8 hours, while C and A can complete it in 12 hours.
I think it clearly shoes that the rates can be arranged in incresing order in such manner: B>A>C
so time can be arranged in C>A>B. The only answer that fits this is
C) 16, 9.6, 48

Answer without any calculations
Join the discussion

Re: work problems

by taichka123 » Sat Oct 18, 2008 6:11 am
Morgoth wrote:
taichka123 wrote:
2) 1/4 of a work is completed by 8 persons in 12 days. Find the number of persons required to complete the remaining work in 16 days.

A)2
B)3
C)4
D)1
Are you sure about the answer choices.

if 8 people finish 1/4 job in 12 days, you would definitely need more than 8 to finish the remaining job i.e 3/4 in 16 days.

Let me know if I am missing something.

I am getting 18 as the answer.



The answer to the first question is indeed C)
The answer to the second problem is 2 people. ?

Thank you for all of your help!
Join the discussion