Question

a man lent rs.4500 at 30 percent compound interest per annum for 3years. what is the difference between the interest earned by the man in the 2nd year only and the interest earned by the man in the 3rd year only............ please give answer fast​

Answer 1

Answer:

Interest earned by the man on 2nd year

= 4500 × [ { 1 + ( 30 ) } 2 – 1 ] – ( 4500 × 30 × 1 )

100 100

= 4500 × ( 69 ) – 1350 = 3105 – 1350 = Rs. 1755

100

Interest earned by the man on 3rd year

= 4500 × [ { 1 + ( 30 ) } 3 – 1 ] – 4500 × [ { 1 + ( 30 ) } 2 – 1 ]

100 100

= 4500 × ( 1197 ) – 4500 × 69 = 5386.5 – 3105 = Rs.2281.5

1000 100

Therefore, required difference = 2281.5 – 1755 = Rs. 526.5

Answer 2

Compound Interest

Sum of money $= rs. 4500$

Rate of compounding annually$=30\%$

Time $= 3 \ years$

difference of the interest in 3rd year and 2nd year will be $= (interest\ earned \ in \ 3rd \ year)-(interest\ earned\ in \ second \ year)$

Formula that will be used here will be,

$C.I. = Principal (1 + Rate)^{Time }- Principal$

Interest earned  on 2nd year

$4500 \times [ {( 1 + (\frac{30}{100} ) } )^2}- 1 ] - ( \frac{4500 \times30 \times1}{100} )$

$=4500\times [(1.3)^2-1]-1350\\\\=3105-1350=1755$

Hence interest earned in 2nd year only will be Rs. 1755.

Interest earned  on 3rd year

$4500 \times [ {( 1 + (\frac{30}{100} ) } )^3}- 1 ] - 4500 \times [ {( 1 + (\frac{30}{100} ) } )^2}- 1 ]$

$=4500\times [1.197]-1755\\\\=5386.5-3105=2281.5$

Hence interest earned in 3rd year only will be Rs. 2281.5.

difference will be $2281.5-1755=526.5$.

Hence required difference is Rs. 526.5.