Question

For comparison of the ratios, quantities must have the same ___.

Answer 1

The quantities compared by ratio must have the same units. 2 rupees and 50 paise cannot be expressed as ratio as 2 : 50. They should be converted to same units and only then can be expressed as a ratio.
2 rupees = 200 paise [$\because$ 1 rupee = 100 paisa]
Hence, ratio = $\frac{200}{50}=\frac{4}{1}=4:1$