Question

Dominic, Ralf and Peter have just eaten a HUGE Christmas meal. Dominic now weighs half as much as Ralph, and Peter weighs three times as much as Dominic. Together they weigh 720 pounds. How much does Dominic weigh?

Answer 1

The question requires us to form an algebraic expression in order to calculate Dominic's weight, after telling us his weigh with respect to his peers and the sum of their weights. Let D represent Dominic's weight, R represent Ralph's weight and P represent Peter's weight. From the given information, we can form:
2D = R
3D = P
P + R + D = 720
Now, we substitute values into the last equation:
3D + 2D + D = 720
6D = 720
D = 120
Dominic's weight is 120 pounds