The average revenues of 7 consecutive years of a company is Rs 83 lakhs. If the average of first 4 years is Rs 78 lakhs and that of last 4 years is Rs 90 lakhs, find the revenue for the 4th year.
A box is termed as eraser, an eraser is termed as pen, a pen is termed as stick, and a stick is termed as plant. Then in the exam a student will write with ___.