Which of the problems below is not a permutation?

a. the number of ways 20 people can finish in the first three places in a race.

b. how many different kinds of pizza can be made with 12 optional toppings

c. how many ways 15 people can arrange themselves in a straight line

d. how many way is the top 20 hit songs can be arranged my selection 500 current singles.

nada

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58

in 1995, potato plants were taken into space aboard the space shuttle columbia.

step-by-step explanation: