Express $3:20$ as percent.

Deepak bought a basket of mangoes containing $250$ mangoes. $12\%$ of these were found to be rotten. Of the remaining, $10\%$ got crushed. How many mangoes were in good condition?

In a Maths Quiz of $60$ questions, Chandra got $90\%$ correct answers and Ram got $80\%$ correct answers. How much correct answers did each give? What percent is Ram's correct answers to Chandra's correct answers?

In an examination, the maximum marks are $900$.A student gets $33\%$ of the maximum marks and fails by $45$ marks. What is the passing mark? Also, find the pass percentage.

In a train, $15\%$ people travel in first class and $35\%$ travel in the second class and the remaining travel in the A.C. class. Calculate the percentage of A.C. class travellers.