In ΔABC, D and E are points on side AB and AC respectively. DE is parallel to BC. If lengths of AD, DB and DE are 8 cm, 6 cm and 7.2 cm respectively, find length of BC?
The average revenues of 9 consecutive years of a company is Rs 65 lakhs. If the average of first 5 years is Rs 60 lakhs and that of last 5 years is Rs 72 lakhs, find the revenue for the 5th year.