Ionly need part b. use the graph to determine the function's range

The answer to this question is (-∞, 0] U {3}

We use the open bracket for infinity since the graph can never reach "infinity"; however, as you decrease the value of x, the graph approaches infinity.

We use a closed bracket for 0 because the range reaches 0, but then stops.

Finally, we use the single bracket for 3 because 3 is in the range, but there is no other bounds for that part of the range.

I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.