Nina makes 8 origami frogs in 36 minutes. At that rate, how many origami frogs can she make in 90 minutes?

Answer: 20 origami frogs.

Step-by-step explanation: This is simple proportion problem

Number of origami frogs made in 36 minutes = 8

Therefore we first need to solve for number of origami frog Nina can made in 1 minute

36 minutes = 8

1 minute = 8/36

= 2/9 origami frogs

Therefore, in 90 minutes, Nina will make = 2/9 * 90/1

= 20 origami frogs.