This is what I got I hope it can help you
Exponential.
One way to think about this, is to ask how much you will lose each year. The first year you're losing 20% of $20,000 ($4,000). The second year you're losing 20% of 16,000 ($3,200). The dollar value your car loses each year diminishes exponentially, so it is not a linear but an exponential function.
Answer
42
Explanation
Let’s say:
Set of envelopes: {a,b,c,d,e,f,g}
Set of postage stamps: {1,2,3,4,5,6}
For an envelope you can have:
1a 2a 3a 4a 5a 6a (6 different combinations)
This applies to all 7 different types of envelopes.
Therefore 7 • 6 = 42
