GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
A machine produces nuts at 100 nuts/min and needs to be cleaned after
[#permalink]
15 May 2021, 23:12
15 May 2021, 23:12
1
6
Bookmarks
00:00
Question Stats:
74% (02:32) correct
25% (02:32) wrong based on 55 sessions
Hide Show timer Statistics
A machine produces nuts at 100 nuts/min and needs to be cleaned after producing every 1000 nuts for 5 minutes . Another machine produces bolts at 75 bolts/min and needs to be cleaned after every 1500 bolts for 10 minutes.
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
Quantity A |
Quantity B |
Time (in minutes) required to produce 9000 pairs of nuts and bolts when both the machines start together |
130 |
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
Re: A machine produces nuts at 100 nuts/min and needs to be cleaned after
[#permalink]
16 May 2021, 09:23
16 May 2021, 09:23
2
1
Bookmarks
I think that the answer is A:
>Nut Machine:
rate: 100 nut/min
cleaning interval: 1000 nut / 1 cleaning
cleaning rate: 5 min/ 1 cleaning
>Bolt Machine:
rate: 75 bolt/min
cleaning interval: 1500 bolt / 1 cleaning
cleaning rate: 10 min/1 cleaning
9000 pairs nuts and bolts = 9000 nuts + 9000 bolts
Find max( minToComplete( nut,9000 ), minToComplete( bolt,9000 ) ):
minToComplete = min to clean + mins to produce
*production time "ends" after last obj. is produced, not last cleaning
>Nut Machine:
number cleanings = (9000 nut - 1000 nut)/ 1000 (nut/cleaning) = 8 cleanings
min to clean = 8 cleanings * (5 min / 1 cleaning) = 40 min
min to produce = 9000 nut * (1 min / 100 nut) = 90 min
min to complete = 40 min + 90 min = 130 mins
>Bolt Machine:
number cleanings = (9000 bolt -1500 bolt )/ 1500 (bolt/cleaning) = 5 cleanings
min to clean = 5 cleanings * (10 min / 1 cleaning) = 50 min
min to produce = 9000 bolt * (1 min / 75 bolt) = 120 min
min to complete = 50 min + 120 min = 170 min
***max(130, 170) = 170
so a total of 170 minutes is required to produce 9000 pairs of nuts and bolts when both machines start together (nut machine finishes first, bolt machine finishes 40 mins later).
A: 170
B: 130
Answer: A, Quantity A is greater
>Nut Machine:
rate: 100 nut/min
cleaning interval: 1000 nut / 1 cleaning
cleaning rate: 5 min/ 1 cleaning
>Bolt Machine:
rate: 75 bolt/min
cleaning interval: 1500 bolt / 1 cleaning
cleaning rate: 10 min/1 cleaning
9000 pairs nuts and bolts = 9000 nuts + 9000 bolts
Find max( minToComplete( nut,9000 ), minToComplete( bolt,9000 ) ):
minToComplete = min to clean + mins to produce
*production time "ends" after last obj. is produced, not last cleaning
>Nut Machine:
number cleanings = (9000 nut - 1000 nut)/ 1000 (nut/cleaning) = 8 cleanings
min to clean = 8 cleanings * (5 min / 1 cleaning) = 40 min
min to produce = 9000 nut * (1 min / 100 nut) = 90 min
min to complete = 40 min + 90 min = 130 mins
>Bolt Machine:
number cleanings = (9000 bolt -1500 bolt )/ 1500 (bolt/cleaning) = 5 cleanings
min to clean = 5 cleanings * (10 min / 1 cleaning) = 50 min
min to produce = 9000 bolt * (1 min / 75 bolt) = 120 min
min to complete = 50 min + 120 min = 170 min
***max(130, 170) = 170
so a total of 170 minutes is required to produce 9000 pairs of nuts and bolts when both machines start together (nut machine finishes first, bolt machine finishes 40 mins later).
A: 170
B: 130
Answer: A, Quantity A is greater
Re: A machine produces nuts at 100 nuts/min and needs to be cleaned after
[#permalink]
19 Nov 2022, 03:29
19 Nov 2022, 03:29
1
\(rt = w\)
For nuts, time would be
\(\frac{9000}{100}=90\) mins
Clean: every 1,000 nuts for 5 minutes so
9,000 nuts = \(9*5=45\)
Total time for nuts \(90+45=135\) minutes
For bolts, applied the same
\(\frac{9000}{45}=120\) minutes
Clean: every 1,500 bolts for 10 minutes
so, \(\frac{9000}{15}6\)
\(6*10=60\) minutes
Total time for bolts \(120+60=180\) minutes
However, it start at the same time so \(180-135=45\)
Total time \(135+45=180\) mins
Hence A since \(180>130\)
For nuts, time would be
\(\frac{9000}{100}=90\) mins
Clean: every 1,000 nuts for 5 minutes so
9,000 nuts = \(9*5=45\)
Total time for nuts \(90+45=135\) minutes
For bolts, applied the same
\(\frac{9000}{45}=120\) minutes
Clean: every 1,500 bolts for 10 minutes
so, \(\frac{9000}{15}6\)
\(6*10=60\) minutes
Total time for bolts \(120+60=180\) minutes
However, it start at the same time so \(180-135=45\)
Total time \(135+45=180\) mins
Hence A since \(180>130\)
