Question

If five spiders can catch five flies in 5 minutes, how many flies can one hundred spiders catch in 100 minutes?

• A. 100
• B. 1000
• C. 500
• D. 2000

Hint:

Use the “unit method”: first compute the rate for one agent per unit time, then scale by time and number of agents.

Answer 1

The Correct Option is D

Step 1: Find per-spider rate.
Five spiders catch 5 flies in 5 minutes $⇒$ in 5 minutes, each spider catches 1 fly.
So, one spider’s rate $= \dfrac{1\ \text{fly}}{5\ \text{minutes}}$.
Step 2: Scale by time (100 minutes).
In 100 minutes, one spider catches $\dfrac{100}{5}=20$ flies.
Step 3: Scale by number of spiders (100 spiders).
Total flies $= 100 \times 20 = 2000$. \[ \boxed{2000} \]