Answer
\$300 is the Private Savings in the economy
Work Step by Step
In a Closed Economy, given that
Income, Y = \$ 1000 ; Government Spending, G = \$ 200; Taxes, T = \$ 150
Investment, I = Savings, S = \$250
Total Savings = Private Savings + Public Savings
Public Savings = Taxes - Government Spending = T - G = \$150 - \$200 = -\$50
Which implies that,
Private Savings = Total Savings(=Total Investment) - Public Savings
= \$250 - (-\$50) = \$250 + \$50 = \$300