7. There are seven clarinet players in the concert band. In how
many ways can they be seated in seven chairs at a concert?
Use the Fundamental Counting Principle.

A. 5,040
C. 840
B. 2,520
D. 210

5,040

Step-by-step explanation:

Fundamental Counting Principle states that if there are m ways of doing a thing and there are n ways of doing other thing  then there are total m*n ways of doing both things.

Example : If there are 5 path to reach a destination and 3 mode of transport ( bike, car, bicycle) . Then are 5 * 3 ways to reach the destination using the different mode of transport available.

Given no of clarinet players = 7

no of chairs = 7

First player can be seated on seven chairs in seven ways

( for illustration let the seat be a , b, c , d , e , f , g. he can sit on any of the chairs)

since one chair is occupied and 6 chair is available

second player can be seated on 6 chairs in 6 ways

for illustration let the seat be a be occupied then b, c , d , e , f , g are  the chairs on which second player can sit.

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Similarly 3rd, 4th, 5th, 6th and 7th player can be seat on chairs in

5, 4 , 3, 2, and 1 way respectively.

now using  fundamental Counting Principle

since 7 players can sit on chair in

7 , 6, 5 , 4, 3 , 2, 1 ways then together they can be seated in

7 *  6 * 5 *  4 * 3 * 2 * 1 ways = 5, 040 ways

do your own work and don"t cheat.

step-by-step explanation:

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺