Hi
How much 'less' is the sum of all odd digits 'between' 24 and 308
than the sum of all even digits 'between' 23 and 307?
306 = 26 + (n-1)2
306 = 26 + 2n - 2
282 = 2n
n = 141
= 23,406 |sum of evens
305 = 25 + 2n-2
141 = n
141/2(50 + 280) = 141/2*330 = 23,265 |sum of odds
23,406 - 23,265 = 141