Ans=24
You need to use Pythagorean theorem.
A^2+b^2=c^2
X^2+32^2=40^2
X^2+1024=1600
1600-1024=576
576=x^2
Square root of 576=x=24
Three hours after the bus starts out, it's 150 miles ahead of the truck. Then the truck starts out, and it gains (65-50)=15 miles on the bus every hour. If neither of them ever stops for anything, the truck will catch up to the bus in ( 150/15 ) = 10 hours. . . . (The hint is useless.)
The best estimate of the solution to this system of equations is about (23,14)
Given:
Book club A charges $20 for membership and $2 per book rental.
Book club B charges $10 for membership and $3 per book rental.
To find:
The number of books for which the cost be the same at both book clubs.
Solution:
Let x be the number of books.
Book club A charges $20 for membership and $2 per book rental. So, the total cost is
...(i)
Book club B charges $10 for membership and $3 per book rental. So, the total cost is
...(ii)
Equating (i) and (ii), we get



The total cost is



Therefore, the total cost at both book clubs are same for 10 rental books and that cost is $40.
I'm pretty sure that the answer is B.