Answer:
-42
Explanation:
Looking at the numbers I can tell that it's decreasing at a constant rate (as in the rate of change is constant). This means that we're dealing with an arithmatic sequence and the common difference is -5. The equation we want is as follows
a+(n-1)d
Where a is the beginning value
n is the nth germ
d is the common difference
we have
3+(10-1)*-5
3+(9)*-5
3-45
-42