Problema Solution
it take 7 hours for isabella to rake leaves by herself, but her brother matthew can work three times as fast. if they work together, how long will it take them to rake leaves
Answer provided by our tutors
Isabella's rate is: 1/7 leaves per hour
Matthew is 3 times as fast thus his rate is: 3/7 leaves per hour
Let 'x' represent the hours they need to rake the leaves together.
The together rate is: 1/x leaves per hour
Now we can write the equation:
1/7 + 3/7 = 1/x
........
click here to solve the equation for x
........
x = 1.75 hr
x = 1 hr 0.75*60 min
x = 1 hr 45 min
It will take them 1 hour and 45 minutes to rake the leaves together.