To find out how many pages Keli reads in 1 day, you can divide the total number of pages she read (100 pages) by the number of days it took her (5 days):
Pages read in 1 day = Total pages read / Number of days
Pages read in 1 day = 100 pages / 5 days
Pages read in 1 day = 20 pages
So, Keli reads 20 pages in 1 day.