Question

A high school purchases two workbooks for every textbook, and two journals for every  workbook. If the school purchases 301 total items, how many of each do they need?

Answer 1

Let
w = number of workbooks
t = number of textbooks
j = number of journals

If the school purchases 1 textbook, it purchases 2 workbooks
∴ w = 2t

If the school purchases 1 workbook, it purchases 2 journals
∴ j = 2w
∴ j = 2 * (2t)
∴ j = 4t

The school purchases a total of 301 items
∴ w + t + j = 301
∴ 2t + t + 4t = 301
∴ 7t = 301
∴ t = 301 / 7
∴ t = 43

∴ w = 2t = 43 * 2 = 86
∴ j = 4t = 4 * 43 = 172

Therefore,
No. of workbooks = 86
No. of textbooks = 43
No. of journals = 172