Question

Which one of the following scenarios can be modeled by an exponential function?(1 point)
Responses

the number of weeds in a garden that decreases by 20 per hour when the garden owner pulls the weeds
the number of weeds in a garden that decreases by 20 per hour when the garden owner pulls the weeds

the number of weeds in a garden that decreases by 200 each week when the landscaper pulls the weeds
the number of weeds in a garden that decreases by 200 each week when the landscaper pulls the weeds

the number of weeds in a garden that decreases by 25% each week when the gardener pulls the weeds
the number of weeds in a garden that decreases by 25% each week when the gardener pulls the weeds

the number of weeds in a garden that decreases by a different amount each week depending on who pulls the weeds

Answer 1

The number of weeds that decreases by 25% each week.

Reason: exponential change multiplies by a constant factor each period (here ×0.75 per week), e.g. N(t) = N0(0.75)^t. Fixed amounts (−20, −200) are linear, and a varying amount is not exponential.