Question

A textbook store sold a combined total of 206 math and physics textbooks in a week. The number of physics textbooks sold was 60 less than the number of math textbooks sold. How many textbooks of each type were sold?

Answer 1

Let p represent # of physics texts sold

Let m represent # of maths texts sold

Therefore we have p = m - 60 | because physics texts sold are less than maths by 60

Total sold = 206 = m + p | recall that p = m - 60

We then have 206 = m + m - 60

206 = 2m - 60 | adding 60 to both sides, we have

206 + 60 = 2m | dividing both sides by 2

266/2 = 2m/2

Therefore, m = 133 texts

and p = m - 60 = 133 - 60 = 193