JNU SSS 2012 Question 22: Keynesian cross and the multiplier

Consider a closed economy in which aggregate output in short-run equilibrium is equal to the level of effective demand. There are only two types of expenditure on goods and services—private consumption expenditure and expenditure by the government $(G)$. Workers earn only wage income and non-workers earn all remaining income. Non-workers always spend a fixed amount on consumption. Suppose to produce every rupee of final output, 0·005 labour-day is required and the wage for a working day is Rs 150.

Suppose there is no taxation in the economy. If $S$ denotes private savings and $I$ denotes investment expenditure in the economy, which of the following is a condition for short-run equilibrium in the economy?