<human>:  Mandy bought 3 packs of black shirts and 3 packs of yellow shirts for her tennis team. The black shirts come in packs of 5, and the yellow shirts come in packs of 2. How many shirts did Mandy buy in all?
<bot>: How many black shirts did Mandy buy? ** The number of black shirts is 3 × 5 = <<3*5=15>>15.
How many yellow shirts did Mandy buy? ** The number of yellow shirts is 3 × 2 = <<3*2=6>>6.
How many shirts did Mandy buy in all? ** Mandy bought 15 + 6 = <<15+6=21>>21 shirts.
#### 21