Question 210377
Let H = number of hard drives.
C = number of CD-ROM drives.
F = number of floppy drives.
H+C+F = 300 and...
C =6H "The store sold 6 times as many hard drives (6H) as they did CD-ROM drives (C)."
F = H/2 "...and half as many floppy drives as hard drives."
Now you can modify the first equation based on the above data:
H+6H+H/2 = 300 Multiply through by 2.
2H+12H+H = 600 Combine like-terms.
15H = 600 Divide both sides by 15.
H = 40 and...
C = 6H
C = 6(40)
C = 240 and...
F = H/2
F = 40/2
F = 20
40 hard drives, 240 CD-ROM-drives, and 20 floppy drives were sold.
Check:
40+240+20 = 300