This production puzzle looks like a multiplication problem, but the key is understanding the rate of each machine.
If 5 machines make 5 toys in 5 minutes, that means each machine makes 1 toy in 5 minutes.
Now imagine you have 100 machines working at the same rate. In the same 5-minute period, each machine can make one toy.
So 100 machines would make:
100 toys in 5 minutes.
The correct answer is therefore 5 minutes.
The trap is assuming that because the number of machines and toys increased from 5 to 100, the time must increase too. But the machines are working simultaneously, so adding more machines increases output without increasing the time needed for one production cycle.
Answer: 5 minutes.


