How long does it take to print 1 page for each typeface?

Question

This is from Page 226, #21 of Fundamentals of Technical Mathematics (2nd edition): An impact printer prints 1 page using regular type and 3 pages using bold type in 23 seconds. If the printer prints 2 pages using regular type and 4 pages using bold type in 34 seconds, how long does it take to print 1 page for each typeface?

Answer 1

x time spent for printing of regular type
y time spent for printing of bold type

1x+3y=23
2x+4y=34
x+y=?

x=23-3y
2(23-3y)+4y=34
46-6y+4y=34
46-34=6y-4y
12=2y

y=6
x=23-3*6=5

x+y=11seconds

:)