Jayden has been reading a 275275275-page book for english class. on average, he has read about 101010 pages in 151515 minutes (\text{min})(min)left parenthesis, m, i, n, right parenthesis. with a deadline looming, jayden realizes that he won't finish in time unless he skims through the rest of the book. if he skims the book, he can cover 151515 pages in 10\,\text{min}10min10, space, m, i, n. if it takes jayden 555 hours and 50\,\text{min}50min50, space, m, i, n to finish the book (reading and skimming combined), how many pages did jayden have to skim through?

75 pages.
   OK. Lots of copying errors here. I'll be using 275 page book, reading 10 pages per 15 minutes, skimming 15 pages per 10 minutes, 5 hours and 50 minutes to complete the book.
   To make things easier, first convert the time to just minutes. So 5 * 60 + 50 = 300 + 50 = 350 minutes.

   Now let's use the variable X for the number of minutes spent skimming and (350-X) for the number of minutes spent reading.
 X * 15/10 + (350 - X)*10/15 = 275

   Solve for X.
 X * 15/10 + (350 - X)*10/15 = 275
 X * 15/10 + 350*10/15 - X*10/15 = 275
 X * 15/10 - X*10/15 = 275 - 350*10/15
X(15/10 - 10/15) = 275 - 3500/15
 X(45/30 - 20/30) = 825/3 - 700/3
 X(25/30) = 125/3
 X = 125/3 * 30/25 = 125/1 * 10/25 = 5/1 * 10/1 = 50/1 = 50
   So Jayden spent 50 minutes skimming. And at the rate of 15 pages every 10 minutes, he skimmed 50*15/10 = 750/10 = 75 pages.