Question

A textbook store sold a combined total of 332 history and chemistry textbooks in a week. The number of chemistry textbooks sold was 84 less than the number of history textbooks sold. How many textbooks of each type were sold?

Answer 1

208 history books

124 chemistry books

Explanation:

Let a = total number of books

b = number of history books

c = number of chemistry books

a = b + c

We know that a is equal to 332 and c = b - 84

Let's substitute this value to our equation and solve for b first. Now we get:

332 = b + ( b - 84)

332 = 2b - 84

332 + 84 = 2b

416 = 2b

b = 208

Now we can solve for c

332 = 208 + c

332 - 208 = c

c = 124

Now let's check

a = 332

b = 208

c = b - 84 = 208 - 84 = 124