Problema Solution
Jessica can vacuum the house in 5 hours. If Dan helps, it takes them 2 hours. Without help, how long would it take Dan to do the same thing?
Answer provided by our tutors
If Jessica vacuums the house in 5 hours and Dan does the same thing alone in 'x' hours then in 2 hours we have
2/5 + 2/x = 1
x = 2 / (1 - 2/5)
x = 10 / 3 = 3 hours 20 minutes
Dan vacuums the whole house alone in 3 hours 20 minutes.