Walkabout wrote:

(0.0036)(2.8) / (0.04)(0.1)(0.003) =

(A) 840.0

(B) 84.0

(C) 8.4

(D) 0.84

(E) 0.084

With these kinds of equations the best thing to do is move the decimal places to the right, remember, what you move in the numerator has to occur in the denominator.

1) ORIGINAL EQUATION: (0.0036)(2.8) / (0.04)(0.1)(0.003)

2) MOVE 2.8 TWO PLACES TO THE RIGHT AND MOVE 0.04 TWO PLACES TO THE RIGHT, EQUATION THEN BECOMES: (0.0036)(280) / (4)(0.1)(0.003)

YOU CAN NOW DIVIDE 280 BY 4 - CANCEL OUT THE FOUR AND THE 280 BECOMES 70

3) MOVE 0.0036 ONE PLACE TO THE RIGHT AND MOVE 0.1 IN THE DENOMINATOR ONE PLACE TO THE RIGHT, EQUATION THEN BECOMES: (0.036) (70) / (1) (0.003)

4) AGAIN MOVE 0.036 TWO PLACES TO THE RIGHT AND MOVE 0.003 TWO PLACES TO THE RIGHT, EQUATION THEN BECOMES: (36)(70) / (1)(3)

5) CANCEL OUT THE THREE AND THE 36 TO FURTHER SIMPLIFY, YOUR EQUATION THEN BECOMES 12*70 = 840 WHICH IS ANSWET CHOICE A