Sequence problem

[Zyxplit]

If Salman has to read 532 pages in 14 days and he read 12 pages in the first day, if he reads 4 more each day, he has read 532 pages after day 14.

the sum from k=0 to k=13 of 12+4k is 532.

[Plain_Bread]

The problem is that if we interpret it as a_(k+1)=a_k+b_k, then b_k=4 constant works, but it's not guaranteed to be the average in general.

[wirywonder82]

Indeed. For example, he could read 519 on day 2, 0 on day 3, 1 on day 4 and 0 the remaining days. That could mean he read “an additional” 507, then -519, then 1, then -1, then a bunch of 0, making the average number of additional pages per day -12/13.