Question

If total utility is decreasing as more units are consumed, then marginal utility must be

a. increasing at a decreasing rate
b. positive
c. decreasing at an increasing rate
d. negative
e. decreasing

Kindly tell which is right answer and why

Answer 1

If total utility is decreasing as more units are consumed, then marginal utility must be negative, because total utility is the sum of marginal utilities.
So, the correct answer is:
d. negative.