To find the quantity of money, we can use the equation of exchange in economics, which is represented as:
\[ MV = PY \]
Where:
- \( M \) = quantity of money
- \( V \) = velocity of money
- \( P \) = price level
- \( Y \) = real value of output (real GDP)
From the information provided:
- \( V = 5 \)
- \( P = 2 \)
- \( Y = 2500 \)
First, we need to calculate \( PY \):
\[ PY = P \times Y = 2 \times 2500 = 5000 \]
Now we can use the equation \( MV = PY \) to solve for \( M \):
\[ M \times V = PY \]
\[ M \times 5 = 5000 \]
To find \( M \), divide both sides by 5:
\[ M = \frac{5000}{5} = 1000 \]
Thus, the quantity of money is:
$1,000.
So the correct answer is (b) $1,000.