We have,
A dozen pencils=12 pencils=12×2Rs.each=24Rs.
4 erasers =4×3Rs.each=12Rs.
7 notebook=7×24Rs.each=168Rs.
6 pen=6×10Rs.each=60Rs.
1 clipboard=1×Rs.45=45Rs.
Now,
Total amount
=24+12+168+60+45
=Rs.309
Hence, this is the answer.