Answer: 3.4 h
Explanation:
1) The basis to solve this kind of problems is that the speed of working together is equal to the sum of the individual speeds.
This is: speed of doing the project together = speed of Cody working alone + speed of Kaitlyin working alone.
2) Speed of Cody
Cody can complete the project in 8 hours => 1 project / 8 h
3) Speed of Kaitlyn
Kaitlyn can complete the project in 6 houres => 1 project / 6 h
4) Speed working together:
1 / 8 + 1 / 6 = [6 + 8] / (6*8 = 14 / 48 = 7 / 24
7/24 is the velocity or working together meaning that they can complete 7 projects in 24 hours.
Then, the time to complete the entire project is the inverse: 24 hours / 7 projects ≈ 3.4 hours / project.Meaning 3.4 hours to complete the project.
45/5 = 9 jams a day
x/7 = 9
x= 63 jams a day
Hope this helps!
You factor out the number of common x's and the common number 4.
Hey there! I'm happy to help!
We see that Rosy uses 1/4 of the bottle to wax 2/3 of the car.
We need to 1/3 more to wax the entire car.
1/3 is half of 2/3.
We used 1/4 bottle for 2/3 of the car.
Therefore, we need half of 1/4 bottle for 1/3 more of the car.
1/4×1/2=1/8
We add this to the original 1/4 to see the total amount we used to wax the entire car.
1/4+1/8=3/8
Therefore, Rosy will use 3/8 of the bottle of car wax to wax her entire car.
