Problema Solution
By himself a person can mow his lawn in 40 minutes. With his daughters help they finish in 30 minutes. How long woul it take his daughter to mow the lawn by herself?
Answer provided by our tutors
let her does in x minutes
in 1 minute his daughter laws = 1/x
in 30 min she laws = 30/x
in 30 mins. he laws = 30/40
30/x + 30/40 = 1
=> x= 120 minutes