Try this GRE math practice question that tests your ability to manipulate and compare decimals expressed in exponent form.
Question#74:
Comparing the numbers $10^{49}$ and $2 \cdot 10^{50}$ we may say:

$\quad \textrm{the first exceeds the second by $8 \cdot 10^{1}$}$

$\quad \textrm{the first exceeds the second by $2 \cdot 10^{1}$}$

$\quad \textrm{the first exceeds the second by $8 \cdot 10^{50}$}$

$\quad \textrm{the second is five times the first}$

$\quad \textrm{the first exceeds the second by 5}$
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