Browse · harp

smc

prealgebra intermediate

Problem

\frac{2 ^{1} + 2 ^{0} + 2 ^{- 1}}{2 ^{- 2} + 2 ^{- 3} + 2 ^{- 4}}

equals

(A)

6

(B)

8

(C)

31/2

(D)

24

Solution

We can factorise to give

\frac{2 ^{1} + 2 ^{0} + 2 ^{- 1}}{2 ^{- 3} ( 2 ^{1} + 2 ^{0} + 2 ^{- 1} )} = \frac{1}{2 ^{- 3}} = 8

, which is

8

.

Final answer

B