For this case you can solve the problem by applying a simple rule of three in which we have
520 ---> 100%
800 ---> x
Clearing x we have
x = (800/520) * 100 = 154%
the percentage increase in cost was
154-100 = 54%
answer
the percentage increase in cost was 54%
She reads at 55 pages per hour for 4 hours so 55*4 = 220 pages so far. This means that she read 220 and had 330 left so 220 + 330 = 550 so the book is 550 pages. If she reads 55 pages per hour and there is a total of 550 pages, 550/55 = 10 hours to read the book.
Answer:
3 packages of pencils and 4 packages of crayons
First expand the equation.
-5e+5+6e = -17
Next, combine the like terms.
e+5 = -17
e = -22