Question

One solar pad can raise water temp 1 degree in 30 min. a second solar pad takes 45 min to raise water temp 1 degree in 45 min. Both machines working together. How long will it take to raise the temp 1 degree

Answer 1

1 deg/30 min = .033 deg/min
1 deg/45 min = .022 deg/min
so working together would yield
.033+.022 = .055 deg/min
or
1/.055 = 18.2 min/deg