Which is an average number? -relative atomic mass
-atomic number
-mass number
-nucleaonic number

Given is:

The initial height of the candle is 9 inches.

And rate of burning is 0.5 inches per hour.

Part A:

The ordered pairs are: {(0,9),(1,8.5),(2,8),(3,7.5),(4,7),(5,6.5)}

Here we will subtract 0.5 each time, with increasing the time per hour as the rate of burning is 0.5 inches per hour.

Part B:

Yes, it is a function because each x value has its own y value.

Part C:

Yes, the relation would still be a function. The only difference is the time, the candle reduces its height 0.45 inches per each hour so ordered pairs will be :  (0,9)  (1,8.55) (2,8.1)  (3,7.65)