Raja invested Rs 15000 at the rate of 10% pa for 1yr. If the interest is compounded half yearly. Find the amount received by Raja at the end of the year.?

Explanation: Give p = Rs 15000, R = 10%, n = 1 yr
According to the formula
Amount = P (1 + r / 2 x 100)^{2n}
=15000 (1 + 5 /100)^{2}
= 15000 x (105/ 100)^{2}
=15000 x 21 / 20 x 21 / 20
= Rs 16537.50

Explanation: Given P = Rs 31250, n = 9 months = 3 quarters, R = 16% pa = 4%
Amount = P (1 + R /100)^{n}
31250 ( 1 + 4/ 100)^{3}
=31250 x 26 /25 x 26 /25 x 26/ 25
=Rs 35152
CI = 35152 – 31250 = Rs 3902

The population of a country is 10 crore and it is the possibility that the populating will become 13.31 core in 3 yr. what will be the annual rate percent on this growth?

Explanation: Given that p = 10 crore
Population after n yr = P (1 + R / 100)^{n}
13.31= 10 ( 1+ R/100)^{3}
1331/1000 = (1+ R/100)^{3}
(11/10)3 = (1 + R/100)^{3}
1 + R /100 = 11/10
R / 100 = 11/10 – 1 = 1/10
R = 10%

Explanation: Given that n1 = 6 yr, x = 2 ½ = 5/2
N2 = 8 yr
According to the formual x 1/ n1 = y 1/n2
(5/2)1/6 = y 1/18
Y = (5/2)18/6
Y = (5/2)3 = 5 x 5 x /2 x 2 x 2
Y = 125 / 8