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.
To figure out this question, I first divided 24 into 3, which gives me an answer of 8. then I divided 52 into 7 , which also is 8 . because the two numbers are the same, I know the ratios are equivalent.
Step-by-step explanation:
ah, here you go.
come on, now. you know this now ...
again, mutually exclusive attributes in the table (no overlap here) allow us to add the numbers for a total :
4+2+12+10 = 28 students in total.
how many of those 28 fulfill our desired criteria (has a brother) ?
well, it is the sum of the column "has a brother", as it does not matter, if there is also a sister or not.
so, it is 4 + 12 = 16
therefore, the probability to pick a student randomly, who has a brother is
16/28 = 4/7 = 0.571428571...
