Playing with license plates
My 6-year old son and I have been playing with license plates lately. Here are some of the games:
a) If all the four digits have the same parity you get x point.
b) If all the digits are squares (0, 1, 4, 9) you get y point.
c) If the three first digits and the last three digits add to 1000 you get z point.
Find x, y, and z.
Problem 371 on Project Euler asks how many license plates one has to see for the first three digits of one plate plus the first three digits on another plate to equal 1000.