Number of total students in the class = 60
Number of girls = 15% of 60
==9 Number of boys = 60 - 9 = 51.
Monthly fee of the each girl = Rs 250
Total fee of 9 girls = 9 × 250 = Rs 2,250
Monthly fee of boys = 34% more than girls fees
=250+ Monthly fee of each boy = Rs 335
Total monthly fee of 51 boys = 51 × 335 = Rs 17,085
Total monthly fee of girls and boys = 17,085 + 2,250 = Rs 19,335