human
Mark has 3 tanks for pregnant fish. Each tank has 4 pregnant fish and each fish gives birth to 20 young. How many young fish does he have at the end?
assistant
How many pregnant fish does Mark have? ** He has 4*3=<<4*3=12>>12 pregnant fish
How many young fish do the pregnant fish give birth to? ** They give birth to 12*20=<<12*20=240>>240 fish
#### 240