Question

For a privately developed group housing project, the ratio of total number of dwelling units of HIG : MIG : LIG is 3:2:1. The proposed average size of HIG, MIG and LIG units in sq.m are 100, 60 and 30 respectively. The ratio of the total built up area between (MIG + LIG) to HIG will be 1: \underline{\hspace{1cm}} [in integer].

Hint:

Always assume a common multiplier for ratios (say \(x\)) and multiply by average unit size to get built-up area.

Answer 1

Step 1: Assume number of units based on ratio.
Let the numbers of HIG : MIG : LIG units = \(3x : 2x : 1x\).

Step 2: Calculate total built-up area.
- HIG total area = \(3x \times 100 = 300x\) sq.m
- MIG total area = \(2x \times 60 = 120x\) sq.m
- LIG total area = \(1x \times 30 = 30x\) sq.m

Step 3: Combine MIG + LIG.
\[ \text{MIG + LIG area} = 120x + 30x = 150x \]

Step 4: Ratio of (MIG+LIG) : HIG.
\[ \text{Ratio} = \frac{150x}{300x} = \frac{1}{2} \]

Step 5: Conclusion.
The ratio = 1 : 2.

Final Answer: \[ \boxed{2} \]