Question

A machine can stamp 40 envelopes in 8 mins. How many of these machines working simultaneously are required or needed to stamp 120 envelopes per minutes.​

Answer 1

Answer:  The required number of machines is 24.

Step-by-step explanation:  Given that a machine can stamp 40 envelopes in 8 mins.

We are to find the number of machines that are working simultaneously are required or needed to stamp 120 envelopes per minutes.​

We will be using the UNITARY method to solve the given problem.

In 8 minutes, number of envelopes stamped by a machine = 40.

So, in 1 minute, the number of envelopes stamped by the machine is given by

$\dfrac{40}{8}=5.$

Now, number of machines required to stamp 5 envelopes in 1 minute = 1.

So, number of machines required to stamp 1 envelope in 1 minute is

$\dfrac{1}{5}.$

Therefore, the number of machines required to stamp 120 envelopes in 1 minute is given by

$\dfrac{1}{5}\times120=24.$

Thus, the required number of machines is 24.

Answer 2

Answer:

24 minutes

Step-by-step explanation:

let y be the 120 envelope per minutes.

40/8 = 120/y

40y= 8 x 120

40x =960

x = 960/40

= 24 minutes