Question

Our galaxy, the Milky Way, has a diameter of about $1\times {10}^{21}m$. The largest galaxy known to man, the $\mathrm{IC}1101$, has a diameter of $5\times {10}^{22}m$. The diameter of the $\mathrm{IC}1101$ is about how many times greater than the diameter of the Milky Way?

• A. $5$
• B. $5000$
• C. $50$
• D. $500$

Answer 1

The correct option is C

$50$

Explanation of the correct answer:

We have given that, the Milky Way, has a diameter of about $1\times {10}^{21}m$. The largest galaxy known to man, the $\mathrm{IC}1101$, has a diameter of $5\times {10}^{22}m$.

Suppose $\mathrm{IC}1101$ is $x$ times greater than the Milky Way then,

$$\begin{gathered} \Rightarrow 5\times {10}^{22}=x\left(1\times {10}^{21}\right) \\ \Rightarrow x=\frac{5\times {10}^{22}}{1\times {10}^{21}} \\ \Rightarrow x=50 \end{gathered}$$

Therefore, $\mathrm{IC}1101$ is $50$ times greater than the Milky Way

Hence, option (C) is the correct answer.