In choice 1, the total salary for the month will be Rs. 31000
For choice 2, salary will be 1+2+....+230 which is equal to 231−1
Now, we know that 29 is 512 and so, 218 will be 5122, which will be greater than 250000
Hence, the number 231−1 will obviously be greater than 31000.
Hence, we will prefer choice 2.