Joe goes camping with his dad on a Friday. Joe's dad has 21 marshmallows, and Joe has four times as much marshmallows as his dad. If Joe’s dad roasts a third of his marshmallows, and Joe roasts half of his marshmallows, how many marshmallows did they roast in total?
How many marshmallows does Joe's dad roast? ** Joe’s dad roasts 21/3 = <<21/3=7>>7 of his marshmallows.
How many marshmallows does Joe have? ** Joe has 21*4 = <<21*4=84>>84 marshmallows.
How many marshmallows does Joe roast? ** Joe roasts 84/2 = <<84/2=42>>42 of his marshmallows.
How many marshmallows did they roast in total? ** Joe and his dad roasted 7+42 = <<7+42=49>>49 marshmallows in total.
#### 49