Every 4 weeks, Helen hand washes her silk pillowcases.  It takes 30 minutes to hand wash all of them.  In 1 year, how much time does Helen spend hand washing her pillowcases?
She hand washes them every 4 weeks and there are 52 weeks in a year so she washes them 52/4 = <<52/4=13>>13 times per year
It takes her 30 minutes to hand wash the pillowcases and she does this 13 times per year for a total of 30*13 = <<30*13=390>>390 minutes per year
#### 390