They have $126 for helium because 200 - 42 - 18 - 14 = <<200-42-18-14=126>>126.
They can buy 84 ounces of helium because 126 / 1.5 = <<126/1.5=84>>84
They can fly 9,492 feet up because 84 x 113 = <<84*113=9492>>9,492
#### 9,492