Can someone help with this grade 9 math question?
This is the question:
It takes Laura 40 minutes to clean her room. When her mother cleans Laura's room it only takes 15 minutes. Which of these is closest to the time it would take to clean the room if they both worked together?
A. 11 min
B. 12 min
C. 13 min
D. 14 min
Your help is appreciated!
This is the question:
It takes Laura 40 minutes to clean her room. When her mother cleans Laura's room it only takes 15 minutes. Which of these is closest to the time it would take to clean the room if they both worked together?
A. 11 min
B. 12 min
C. 13 min
D. 14 min
Your help is appreciated!
1 Answer
Jul 22, 2018
A.
Explanation:
I approached it as such:
I determined the rates at which they worked:
Laura: 1 room in 40 mins, so
Laura's mom: 1 room in 15 mins, so
Added their working rates together:
So to find their total mins per room, just reciprocate:
