A manufacturer reckons that the value of a machine which costs him 156250, will depreciate each year by 20%. Find the estimated value at the end of 5 years.

Three years before the population of a village was 10000. If at the end of each year, 20% of the people migrated to a nearby town, what is its present population?

What will 5000 amount to in 10 years, compounded annually at 10% per annum? [Given (1.1)¹⁰ = 2.594]

The number of bacteria in a certain culture doubles every hour. If there were 50 bacteria present in the culture originally, how many bacteria would be present at the end of (i) 2^nd hour, (ii) 5^th hour and (iii) nth hour?

If p, q, r are in AP, then prove that pth, qth and rth terms of any GP are in GP.