Machine A and machine B are each used to manufacture 660 sprockets. It takes machine A 10 hours longer to produce 660 sprockets than machine B. Machine B produces 10 percent more sprockets per hour than machine A. How many sprockets per hour does machine A produces?	Pick one:	A) 6	B) 6.6	C) 60	D) 100	E) 110

Rationale: b takes x hours a takes x + 10 hours rate of a = 660 / x + 10 rate of b = 660 / x thus , 660 / x = ( 660 / x + 10 ) * 1.10 x = 100 so b = 100 a = 110 sprockets per hour 660 / 110 = 6 answer : a
Answer: A