Question 916539
1 hr = 60%; 2 hrs= 75%; 4 hrs = 90% ...
every hour goes up 15%
75% + 10% = 85%
{{{1hr/15 = x/10}}}  x the time to go up 10%
15x = 10
x = 10/15 = 2/3 hr, time to go up 10%
2hrs + 2/3hrs = 2 2/3 hrs, time it would take for 85%