Question: A company has two models of computers, model M and model N. Operating at a constant rate, a model M computer can complete a certain task in 18 minutes and a model N computer can complete the same task in 9 minutes. If the company used the same number of each model of computer to complete the task in 1 minute, how many model M computers were used?

1. 2
2. 3
3. 6
4. 9
5. 12

“A company has two models of computers, model M and model N. Operating at a constant rate, a model M computer can complete a certain task in 18 minutes and a model N computer can complete the same task in 9 minutes. If the company used the same number of each model of computer to complete the task in 1 minute, how many model M computers were used?”- is a topic of the GMAT Quantitative reasoning section of GMAT. This question has been taken from the book “GMAT Official Guide Quantitative Review”. To solve GMAT Problem Solving questions a student must have knowledge about a good amount of qualitative skills. The GMAT Quant topic in the problem-solving part requires calculative mathematical problems that should be solved with proper mathematical knowledge.

Answer: C
Solution and Explanation:
​Approach Solution (1):

Time taken by model M computer to complete 1 work = 18 minutes so Rate of work of model M = 1/18 work/min

Time taken by model N computer to complete 1 work = 9 minutes so Rate of work of model N = 1/9 work/min

1 work was completed in 1min so combined rate of work of x computers of M type and x computers of N type = 1 work/min

x/18 + x/19 = 1

x = 6

Correct Option: C

Approach Solution (2):

Let’s say 1 work is processing 18 gb of data

Model M: 1 gb per min

Model N: 2 gb per min

Working together, 1 M and 1 N = 3 gb per min

So, 6 times as many computers would work at 18 gb per min

So no. of M = 6

Correct Option: C

Suggested GMAT Problem Solving Samples

• The Interior Angles of a Polygon are in Arithmetic Progression GMAT Problem Solving
• For Any Four Digit Number, abcd, *abcd*= (3^a)(5^b)(7^c)(11^d) GMAT Problem Solving
• GMAT Problem Solving- Find the greatest number that will divide 43, 91 and 183
• If \(2^{98}=256L+N\) , Where L and N are Integers and \(0 \leq N \leq 4\) , What is the Value of N? GMAT Problem Solving
• What is the Value of x? 1) x^2 + x + 10 = 16 2) x = 4y^4+2y^2+2 GMAT Problem Solving
• For How Many Values of k is 12^12 the Least Common Multiple GMAT Problem Solving
• Is Square Root = Always Positive? GMAT Problem Solving
• \(\frac{15^{11}-15^{10}}{14}=?\) GMAT Problem Solving
• In a Drawer, There are 4 White Socks, 3 Blue Socks, and 5 Grey Socks GMAT Problem Solving
• A Contractor Estimated that his 10-Man Crew Could Complete the Construction in 110 Days if There Was no Rain. GMAT Problem Solving
• If n = \(3^8\)– \(2^8\), Which of the Following is Not a Factor of n? GMAT Problem Solving
• Two Consultants, Mary and Jim, Can Type up a Report in 12.5 Hours and Edit it in 7.5 Hours. GMAT Problem Solving
• GMAT Problem Solving - The Price of Raw Materials Has Gone up by 15%
• Greg Assembles Units of a Certain Product at a Factory. GMAT Problem Solving
• After 6 Games, Team B Had an Average of 61.5 Points Per Game. GMAT Problem Solving
• If 10, 12 and ‘x’ are Sides of an Acute Angled Triangle, How Many Integer Values of ‘x’ are Possible? GMAT Problem Solving
• There are 100 Apples in a Bag of which 98% are Green and Rest are Red ​ GMAT Problem Solving
• A palindrome is a number that reads the same forward and backward​ GMAT Problem Solving
• GMAT Problem Solving - Iqbal Dealt Some Cards to Mushtaq and himself from a Full Pack of Playing Cards
• A Rectangular Box has Dimensions 12*10*8 Inches GMAT Problem Solving