Earnings of 10 days = ₹1500
Applying unitary method, where firstly we find the value of one unit and then the value of required number of units.
∴ Earning of 1 day =₹150010=₹150
⇒ Earning of 30 days =₹150×30=₹4,500
Thus, the earning of 30 days is ₹4,500.