If a: b :: 3 : 7, then what is (5a+6b): (a-2b)?
Choose the correct choice from the following answers: A) 57 : 11 B) - 57 : 11 C) 11 : 10 D) - 11 : 10 E) - 1 : 10

Rationale: a / b = 3 / 7 dividing numerator & denominator of ' ( 5 a + 6 b ) / ( a - 2 b ) ' by b , [ 5 ( a / b ) + 6 ] / [ ( a / b ) - 2 ] = [ 5 * ( 3 / 7 ) + 6 ] / [ ( 3 / 7 ) - 2 ] = - 57 / 11 answer : b
Answer: B