Question 182307
A computer store sold 300 items last month.

The store sold 6 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 was sold?

Number of Hard Drives = A

Number of CD Rom drives = B

Number of Floppy Drives = C

A + B + C = 300

The store sold 6 times as many hard drives as they did CD-ROM drives:

A = 6B

The store sold half as many floppy drives as hard drives:

C = A/2 (= 3B from above)

Writing A + B + C = 180 in terms of B for A and C:

6B + B + 3B = 300

10B = 300

B = 30 CD Rom drives

A = 180 Hard Drives 

C = 90 Floppy Drives