Question

ron can make as many pizzas in 30 mins as jeff can make in 40 mins. how long will it take to make the same number if they both work?

Answer 1

They both take 17.1 min to make the pizzas.

Explanation:

Ron can do a job in 30 mins =
`(1)/(30)`

Jeff can do a job in 40 mins =
`(1)/(40)`

They both work together =
`$(1)/(40)+(1)/(30)$`

We have to take LCM of 30 and 40 as 120, so that the denominator becomes equal, also we can add them.

=
`(3)/(40 * 3)+(4)/(30 * 4)=(7)/(120)`

Further we get,
`(120)/(7)=17.1 \mathrm{mins}`

They both work for 17 .1 mins to make the same number of pizzas.