Question

A College student bought 11 books for fall classes. If the cost of his physics textbook was 3 times the mean cost of the other 10 books, then the cost of the physics textbook was what fraction of the total amount he paid for the 11 books? a) 2/13 b) 3/13 c) 3/11 d) 3/10

Answer 1

\[\Huge\cal{\frac{\text{cost of the physics text book}}{\text{total cost}}}\]

Answer 2

\[\Huge{\frac{3x}{3x+10x}}\]here \(x\) is the mean cost of other 10 books.