The access code for a security system has five numbers. How many different codes are there if repetition is allowed but the first and second numbers have to be less than four-
and - the third, fourth, and fifth numbers each have to be greater than 4?

pretty sure it's just 9

Step-by-step explanation:

Let's assume the possible numbers are 1,2,3,4,5

There are only 3 numbers less than 4 (1,2,3) which means that there are 3*3 possbiblities out of the two spots

There's only 1 number greater than 4 (5) which means the third, fourth, and fifth are just 5

which means the answer is just 9

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