Solution:

Simple interest = PNR/100

= (25000 x 1 x 14)/100

= 3500

Amount = principal + interest

= 25000 + 3500

= 28500

Amount at the end of the first year = 28500

Amount at the end of second year = 28500 + 3500

= 32000

Amount at the end of third year = 32000 + 3500

= 35500

28500,32000,35500.,………………….

This is the arithmetic sequence. To find the amount of investment after 20 years we need to find 20th term

tn = a +(n - 1) d

a = 28500 d = 32000 – 28500

= 3500

t20 = 28500 + (20 - 1) 3500

= 28500 + 19 (3500)

= 28500 + 66500

= 95000