5 drill machines can drill 15 meters in 5 hours.

Question

5 drill machines can drill 15 meters in 5 hours. Assuming the speed of each machine to be the same, how many machines would be needed to drill 60 meters in 2 hours?

A)8
B)16
C)23
D)50
E)60

NomanSaleem · Answer

Mac 5 meters 15 hours 5 
Mac x meters 60 hours 2 
Do it with proportion. 
X/5= 60/15 * 5/2
X=50

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chetan2u · Answer

to drill 15 mtr in 5 hrs, 5 machines are required..
so to drill 15*4 mtr in 5 hrs, 5*4 machines are required..
to drill 60 mtr in 1 hrs, 20*5 machines are required..
finally to drill 60 mtr in 2 hrs, 100/2 or 50 machines are required..

D

generis · Answer

Find a machine's individual rate from the first information, and use it to solve the question.

W = (# of machines) * (indiv.) rate * time
W = 15, # of machines = 5, rate = ??, time = 5

15 = 5 * rate * 5
15 = 25 * rate

Individual rate =  \frac{15}{25}=\frac{3}{5}  in meters/hour

At that rate, how many machines are needed to drill 60 meters in 2 hours?

W = (# of machines) * (indiv.) rate * time
W = 60, # of machines = ??, rate =  \frac{3}{5} , time = 2

60 = (# of machines) *  \frac{3}{5}  * 2
60 = (# of machines) *  \frac{6}{5}

# of machines  =  \frac{60}{(\frac{6}{5})}= 60 * \frac{5}{6}=   50

Answer D

JeffTargetTestPrep · Answer

The rate for 5 drill machines is 15/5 = 3 meters per hour. We need to determine how many drill machines we need for a rate of 60/2 = 30 meters per hour. Since 30 is 10 times 3, we would need 5 x 10 = 50 drill machines.

Answer: D

MathRevolution · Answer

\frac{(M_1 * H_1)}{W_1} = \frac{(M_2 * H_2)}{W_2}

=> \frac{(5 * 5)}{ 15} = \frac{(M_2 * 2)}{ 60}

=> M_2 = \frac{(5 * 5 * 60) }{ (15 * 2)}

=> M_2 = 50

Answer D

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5 drill machines can drill 15 meters in 5 hours.

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