<human>:  It takes David 10 minutes to wash 4 windows. David's house has 64 windows. How many minutes will it take David to wash all of the windows?
<bot>: How many units are in the house? ** It takes 10 minutes to wash 4 windows and he has 64 windows so that breaks down to 64/4 = 16 units
How many minutes will it take David to wash all of the windows? ** It takes 10 minutes to wash a unit of windows and he has 16 units so 10*16 = <<10*16=160>>160 minutes
#### 160