A textbook store sold a combined total of 474 chemistry and sociology textbooks in a week. The number of chemistry textbooks sold was two times the number of sociology textbooks sold. How many textbooks of each type were sold? What was the number of chemistry textbooks sold and number of sociology textbooks sold:

Answer :

474 books = X + Y

If X = 2Y, then replace

474 = 2Y + Y = 3Y

then

Y = 474/3= 158

Then if X is, chemistry books number

X = 2•158 = 316

So then answer is

Chemistry books= 316

Sociology books= 158