# math

posted by on .

A computer store sold a total of 300 items last month. The store sold six times as many
hard drives as they did CD-ROM drives, and half as many floppy drives as hard drives.
Based on this information, how many of each item were sold?
A. 30 hard drives, 90 floppy drives, and 180 CD-ROM drives
B. 40 hard drives, 20 floppy drives, and 240 CD-ROM drives
C. 180 hard drives, 90 floppy drives, and 30 CD-ROM drives
D. 240 hard drives, 20 floppy drives, and 40 CD-ROM drives

could someone plz help!

• math - ,

H = hard drives
C = CD-ROM
F = floppy drives.
==================
H = 6C
F = (1/2)*6C = 3C
H + C + F = 300
Substitute 6C for H and substitute 3C for F and solve for C, then H, then F.

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A and B do not fit the required 6:1 hard drive/CD drive ratio. That leaves C and D

Apply the hard/floppy ratio criterion (1:2) to see which it is.

• math - ,

The store sold six times as many
hard drives as they did CD-ROM drives . . .

The next part:

half as many floppy drives as hard drives . . .

Which of the two meets that criterion?

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Right.

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thanks everyone!