Question

Find the principal amount on which the difference of interest for 9 months yearly and quarterly is 18. 30 at 20% p.a.

Answer 1

soln.
Amount (a) =18.30
Time. (t) = 9 month's 9/12 years n. =0.75years
Rate. (r)= 20
Principal (p) = ?
by using formula
P = A × 100
__________
100+TR
or, 18.30 × 100
_________
100+0.75× 20
or, 1830
______
100+15
or, 1830
_____
115
or, 15. 913
.
. . == 15.913
Hence the principal is 15 .913

Answer 2

Answer:

2400

Step-by-step explanation:

solution= calculate 3 months

r=20% 6 month r=10% 3month r=5% 9 month r=15%

3months CI

so, A=P(1+r/4x100)4n-1

P(1+5/100)4x3/4-1

P(115/100)3-1

P(1.157625-1)

A=P(0.157625)---------------1

1year CI

so, A=P(1+r/100)n-1

P(1+15/100)-1

P(115/100)-1

P(1.15-1)

A=P(0.15)----------------------2

Amount difference = P1-P2

A=0.157625-0.15

A=0.7625

CI difference = 18.30

P=18.30/0.7625X100

P=2400 Answer