Jose makes 1 / 1.5 of the job per hour. It is his rate of work in addition to that the partner makes 1 / 4.5 of the job per hour. It is his rate of work.
Thus:
1 / 1.5 + 1 / 4.5 = 1 / x
0.8898 = 1 / x
x = 1 / 0.8888
x = 1.125
Hence, it will take 1 hour and 7.5 minutes for them to complete the job working together.
