Dinosaur Math

Randy Weiss found this truly fascinating sign at the entrance of Utah. Up to this point the math in our signs has been composed of mainly units in miles or road numbers, with an occasional exit number added for fun. This sign will have none of that. Instead, this sign brings dollars, years and days into it's mathematical beauty! Randy captured this picture under close scrutiny from the park ranger, and recommends the Dinosaur Park to anyone that passes through the area -- not just for this sign either!



With all the numbers being divisible by 5, it looks at first glance that this sign has a mathematical connection. With a second glance the 62 pops out, a burn job for sure. Then the third glance reveals the 7. After that, it all clicks together.

$$\matrix{62 - 7 + 20 = 65 + 50 + 10 - (5 \times 10)\cr \Downarrow\cr 55 + 20 = 125 - 50\cr \Downarrow\cr 75 = 75}$$

This sign is found on the right side of the road as you approach the ranger station to pay your fee.