A very unique computer engineer wanted advertisement photos

It is an advertisement photograph of a very unique computer engineer wanted. "I'm looking for a computer engineer who can solve a difficult problem, please contact me with this number right away." If you solve a difficult equation, the answer will be the phone number. It is quite a witty idea.

Details are as below. But actually looking at the problem makes it easy to solve by mental arithmetic, so is it the first-come-first-served?
Mckinsey on Flickr - Photo Sharing!


By the way the problem is here.
X = 24, Y = 30
Phone: = 01. (Y² - X). (Y² - 10²) × 10