Suppose that this person drives at r mph going to the mountains, and gets there in 12 hours. Returning, this person drives at (r+20) mph and gets home in 8 hours. We don't know the distance yet, but can solve for the initial speed, r, by setting
d = 12r = (r+20)(8). Solving for r, r=40 mph (going) and (40+20)mph = 60 mph (returning. Since d=12 r, d = (12 hrs)(40 mph) = 480 miles (answer).
Answer:
One: 58.5
Two 36.6
Step-by-step explanation:
One
20 students * 65 = 1300 This is the total score of all 20 students. They may not all get 65, but 1300 is what their average total is.
20 students * 52 = 1040
The total score of all 40 students was 1300 + 1040 = 2340
The average for the entire class was 2340 / 40 = 58.5
Two
This question is done almost the same way.
Supposes the total number of members is 100. That means that 28 of them are men
28 * 33 = 924 This is the total age for the men
100 - 28 = 72 Out of 100, 72 of the people there are women.
72 * 38 = 2736
The total number of years of all of the members is
924 + 2736 = 3660
The average age of all members is 3660/100 = 36.6
Why did I pick 100 as the total membership? It is because a percentage is number out of 100. Am I allowed to invent things like that? Sure. I'm just using the definition of a percentage.
The average will make it come out the same.
There are 13 different 4 of a kinds.
4 aces 4 twos 4 threes 4 fours 4 fives 4 sixes 4 sevens 4 eights 4 nines 4 tens
1 2 3 4 5 6 7 8 9 10
4 jacks 4 queens 4 kings
11 12 13
The answer is 13 different sets.
I hope this helps :)
<span>the ratio of the girls to boys in the bird-watching club is 18/9 = 2/1
answer
2/1</span>
