Math
posted by Grace on .
1) Mr.Anderson has 3 passenger seats in his car.He offered to drive some of the 5 members of his daughter's club to the movies. How many different groups of 3 passengers could he drive?
2) A jar has green and red marbles.If the ratio of green to red is 3:2,what is the probability that one marble selected at random will be green?
3)The average of the old integers between 10 and 20 is how much more than the average of the even intergers between 0 and 20?
4) In the River City string ensemble of 15 people, 8 people play the violin and 5 people play the cello. If 2 of these people play both instruments,how many members of the string ensemble play neither of these instruments?

3.
[(2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18)/9]  [(11 + 13 + 15 + 17 + 19)/5] = ? 
1) 5 choose 3
5C3=5!/(3!2!)=10
2)
3 out of 5 is green, so
P(G)=3/5
3) check if "between 0 and 20" includes or excludes the two ends.
4)
Number of people who play at least one of violin or cello
=8+52=11
So four of the members do not play the violin nor the cello.