Combined variation with four variables: Is this even possible to solve?

21 Views Asked by At

I have this problem, and I'm quite confused on how to solve it.

Mr. Plaridel owned a newspaper publication called Diaryong Tagalog Inc. He observed that when he used 3 printing presses, he can produce 405,000 copies of newspapers in 4 hours. He also observed that when he used 2 printing presses, he needed to use 40 liters of fuel to power them for 6 hours. If Mr. Plaridel wished to use one printing press fueled with 10 liters of fuel running for 1 hour, how many copies of newspaper can he print?

I tried it but I had no luck in finding a solution.

1

There are 1 best solutions below

2
On BEST ANSWER

Since $2$ printing presses require $40$ liters of fuel for $6$ hours of work, one printing press requires $20$ liters of fuel for $6$ hours of work, so each printing press requires $10/3$ liters of fuel per hour of work.

Since $3$ printing presses require $4$ hours to produces $405000$ newspapers, one printing press requires $4$ hours to produce $135000$ newspapers, so each printing press produces $33750$ newspapers per hour.

Since $10/3 < 10$, the one printing press Mr. Plaridel wishes to use can indeed run for the full hour he wishes it to be used, so he can print $33750$ newspapers.