Step-by-step explanation:
1 week = 7 days of 24 hours each = 7×24 = 168 hours.
the first team can do 1/700 of the total work per hour.
the second team can do 1/600 if the total work per hour.
if they work together, then 1/700 + 1/600 of the total work can be done per hour.
to add these 2 fractions we need to bring them to the same denominator. and that would be 4200 (LCM of 700 and 600).
1/700 + 1/600 = 6/4200 + 7/4200 = 13/4200
so, together, they can do 13/4200 if the total job in 1 hour.
how many hours will they need together to finish the job ?
well, how often does 13 fit into 4200 (as 4200/4200 is the complete job) ?
4200 / 13 = 323.0769231... hours
so, it will still take a little bit over 323 hours to clean all the streets.
but there are only 168 hours until the film crew starts.
so, no, there is not enough time.
