Question

Express $(3\times {10}^2)+(2\times {10}^1)+(9\times {10}^0)+(2\times {10}^{-1})+(5\times {10}^{-2})$ as a numeral.

• A. 32.925
• B. 3292.5
• C. 329.25
• D. 3.2925

Answer 1

The correct option is C

329.25

For any non-zero integer $a$, we have

• $a^0=1$
• $a^{-m}=\frac{1}{a^m}$

$(3\times {10}^2)+(2\times {10}^1)+(9\times {10}^0)+(2\times {10}^{-1})+(5\times {10}^{-2})$
$=(3\times 100)+(2\times 10)+(9\times 1)+(2\times \frac{1}{10})+(5\times \frac{1}{100})$
$=300+20+9+0.2+0.05$
$=329.25$