Karen can read 10 pages and complete 15 math problems in 30 minutes. How long will it take her to do her homework if she has 30 pages to read and 45 math problems to complete? Your answer should refer to the amount of time in minutes.
Karen can read 10 pages and complete 15 math problems in 30 minutes.
So, she can read 1 page in 30/10 = <<30/10=3>>3 minutes.
She can complete 1 math problem in 30/15 = <<30/15=2>>2 minutes.
Therefore, Karen will need 30 x 3 = <<30*3=90>>90 minutes to read 30 pages.
And she will need 45 x 2 = <<45*2=90>>90 minutes to complete 45 math problems.
Thus, it will take her 90 + 90 = <<90+90=180>>180 minutes to do her homework. Answer: \boxed{180}.