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A company received two shipments of ball bearings. In the fi
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02 Apr 2020, 08:04
02 Apr 2020, 08:04
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Question Stats:
90% (01:32) correct
9% (01:05) wrong based on 32 sessions
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A company received two shipments of ball bearings. In the first shipment, 1 percent of the ball bearings were defective. In the second shipment, which was twice as large as the first, 4.5 percent of the ball bearings were defective. If the company received a total of 100 defective ball bearings, how many ball bearings were in the first shipment?
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: A company received two shipments of ball bearings. In the fi
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02 Apr 2020, 09:28
02 Apr 2020, 09:28
1
Carcass wrote:
A company received two shipments of ball bearings. In the first shipment, 1 percent of the ball bearings were defective. In the second shipment, which was twice as large as the first, 4.5 percent of the ball bearings were defective. If the company received a total of 100 defective ball bearings, how many ball bearings were in the first shipment?
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
Let x = the total number of ball bearings in the first shipment
The second shipment, which was twice as large as the first
So, 2x = the total number of ball bearings in the second shipment
In the first shipment, 1 percent of the ball bearings were defective
So, 1% of x = total number of DEFECTIVE ball bearings in the first shipment
In other words, 0.01x = total number of DEFECTIVE ball bearings in the first shipment
In the second shipment, 4.5 percent of the ball bearings were defective.
So, (0.045)(2x) = total number of DEFECTIVE ball bearings in the second shipment
In other words, 0.09x = total number of DEFECTIVE ball bearings in the second shipment
If the company received a total of 100 DEFECTIVE ball bearings, how many ball bearings were in the first shipment?
We can write: 0.01x + 0.09x = 100
Simplify: 0.1x = 100
Solve: x = 100/0.1 = 1000
Answer: B
Cheers,
Brent
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Given Kudos: 64
GRE 1: Q160 V152
A company received two shipments of ball bearings. In the fi
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27 Jul 2021, 19:03
27 Jul 2021, 19:03
1
Carcass wrote:
A company received two shipments of ball bearings. In the first shipment, 1 percent of the ball bearings were defective. In the second shipment, which was twice as large as the first, 4.5 percent of the ball bearings were defective. If the company received a total of 100 defective ball bearings, how many ball bearings were in the first shipment?
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
A. 990
B. 1,000
C. 2,000
D. 3,000
E. 3,500
Kudos for the right answer and explanation
Alligation applied: shipment proportions = \(1/2\), required ratio = \(100/x\), the solution follows \(1/2 = (0.045-100/x)/(100/x-0.01)\),
\(0.09-200/x = 100/x - 0.01\), \(0.1 = 300/x\), \(x = 3000\). Hence, the first shipment is \(1/3\) of x OR \(1/3*3000=1000\)
