A company offers two salary schemes to a new employee.
Scheme A: monthly salary starts at ₹10,000 and increases by ₹400 every month.
Scheme B: monthly salary starts at ₹8,000 and increases by ₹600 every month.
After how many months will the cumulative salary earned under Scheme B be at least ₹30,000 more than that under Scheme A for the first time?
a) 27
b) 30
c) 31
d) 32