Question 446848
"three times faster than"?

The work of doing 1 job is, making 10000 aluminum cans.


Old machine goes at the rate of {{{1/9}}} jobs per hour.
New land old machine together, {{{1/9+3/9=4/9}}} work rate, jobs per hour.


Time for the new machine on its own, some x hours.
{{{1/9+1/x=4/9}}}

{{{1/x=4/9-1/9}}}

{{{1/x=3/9=1/3}}}


New machine needs 3 hours to do the one job, working on its own.