The file, 90 megabytes in size, downloads at the rate of 5 megabytes per second for its first 60 megabytes, and then 10 megabytes per second thereafter. How long, in seconds, does it take to download entirely?
How many seconds do the first 60 megabytes take? ** The first 60 megabytes take 60/5=<<60/5=12>>12 seconds.
How many megabytes are remaining? ** There are 90-60=<<90-60=30>>30 remaining megabytes.
How many seconds do the remaining megabytes take? ** The remaining 30 megabytes take 30/10=<<30/10=3>>3 seconds.
How long, in seconds, does the file take to download entirely? ** And 12+3=<<12+3=15>>15 seconds.
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