Question: Jason's dog has a tail that's half the length of its body, and a head that's 1/6 the length of its body. If the dog is 30 inches long overall, how long is its tail? Think carefully first, then make a decision:
If b is the length of the body, h is the length of the head, and t is the length of the tail, we know that b + h + t = 30, h = b / 6 and t = b / 2. We can substitute the second two equations into the first equation to get b + b / 6 + b / 2 = 30. Now multiply both sides of this equation by 6: 6b + b + 3b = 180. Now combine like terms: 10b = 180. Now divide both sides by 10: b = 180. The dog's body is 18 inches long. Now divide that length by 2 to find the length of its tail: 18 inches / 2 = 9 inches. So the answer is 9.