2 × 10^1 + 3 × 10^0 + 4 × 10^(–1) + 5 × 10^(–2) =

Question

2 × 10^1 + 3 × 10^0 + 4 × 10^{–1} + 5 × 10^{–2} =

(A) 11.15
(B) 20.131
(C) 23.45
(D) 45.321
(E) 53.231

BrentGMATPrepNow · Answer

2 × 10^1 + 3 × 10^0 + 4 × 10^{–1} + 5 × 10^{–2} =(2 × 10) + (3 × 1) + (4 × 0.1) + (5 × 0.01) 
 =20 + 3 + 0.4 + 0.05 
 =23.45

Answer: C

GMATWhizTeam · Answer

Solution:

We are asked the value of  2 × 10^1 + 3 × 10^0 + 4 × 10^{–1} + 5 × 10^{–2}

⇒ 20+3	imes 1+\frac{4}{10}+\frac{5}{100}  (We know  10^0=1, 10^{-1}=\frac{1}{10}  and  10^{-2}=\frac{1}{100} )

⇒ 23+0.4+0.05

⇒ 23.4+0.05

⇒ 23.45

Hence the right answer is    Option C   .

yasharoraa · Answer

The best way to do this is just to follow  BDMAS  and solve.

Let's solve each of the powers first
 2 × 10 + 3 × 1 + 4 × 0.1 + 5 × 0.01

Then, let's do the multiplications
 20 + 3 + 0.4 + 0.05

Now, we just need to do the additions
 23.45

Hence, the answer is  C .

Shaw9 · Answer

Sol:

20+3+(4/10)+(5/100) = 23+0.40+0.05 = 23.45

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