Question

2. An advertising firm has an old computer that can prepare a whole mailing in 6 hours. With

Answer 1

Answer:

The new model can do the entire work alone in 3 hours.

Step-by-step explanation:

Let us assume that the newer model of computer can complete the job alone in x hours.

Therefore, in one hour this new model can do $\frac{1}{x}$ part of the job.

Again the old model can do the entire job alone in 6 hours,

So, in 1 hour the old model can do $\frac{1}{6}$ part of the job.

Therefore, if they work together, then in 1 hour they will do $(\frac{1}{6} +\frac{1}{x} )= \frac{x+6}{6x}$ part of the job.

So, the entire work they can do together in $\frac{6x}{x+6}$ hours.

So, given that $\frac{6x}{x+6}=2$  

⇒ 6x = 2x + 12

⇒ x = 3 hours,

Therefore, the new model can do the entire work alone in 3 hours. (Answer)