Answer:
Step-by-step explanation:
the first day he used 30 cups
the second day he used 15% of the remaining cups...a total of 90 cups were used on second day.
so 15%of the remaining cups = 90.....so if u let x be the total cups, then the remaining cups would be x - 30
15% of (x - 30) = 90.....turn ur percent to a decimal..." of " means multiply
0.15(x - 30) = 90
0.15x - 4.5 = 90
0.15x = 90 + 4.5
0.15x = 94.5
x = 94.5 / 0.15
x = 630 total cups <==
lets check..
start with 630 cups....used 30 the first day....leaving u with 600 cups....15% of the remaining cups = 90.....so 15% of 600 = 90....lets check it
15%of 600 = 0.15(600) = 90...yep, thats correct....there were 630 cups in the new un-opened box
Answer:
630
Explanation:
15% * number of remaining cups = 90
15% * (x-30) = 90
0.15(x-30) = 90
0.15x - 4.5 = 90
0.15x = 94.5
x = 630
