Amount (A) = Principal (P) + Interest (I) i.e. A = P + I
1 = PTR100
A = 3P; T = 10 years (Given)
Since A = P + I
implies3P=P+P×10×R100
implies3P=P+10PR100
implies3P=P+PR10
implies3P−P=PR10
implies2P=PR10
implies2P1=PR10
implies PR = 20P
∴ R = 20%
Since the rate stays the same
A = 5P; R = 20%;T =?; A =P + I
implies5P=P+p×T×20100
implies5P−P=2PT10
implies4P=2PT10
implies2P=PT10
implies PT = 20P
∴ T = 20 years
