ABCD is a cyclic rectangle. Prove that the centre of the circle through A, B, C
and D is the point of intersection of the diagonals of the rectangle.
Answers
Answer:
Hello............. ^_^
Q. (6)
Let Principal be 'P'
and Rate of interest be 'R'
Time (n) = 2 years
Simple Interest (S.I) = Rs. 400
Compound Interest (C.I) = Rs. 410
S.I=100P×R×T=100P×R×T=400=100PR×2=400=50PR=400=PR=400×50=PR=20000
Rate of interest = 5%
Now Principal,
as PR
NowPrincipal,asP×R=20000=>P×5=20000=>P=520000=>P=4000
Principal = Rs. 4000
Q. (7)
A man invested Rs. 1000 for 3 years at 11% Simple Interest .....................(CASE 1)
Principal (P) = Rs. 1000
Rate of interest (R) = 11% per annum
Time (n) = 3 years
S.I=100P×R×T=1001000×11×3=10×11×3=330
S.I = Rs. 330
He also invested Rs. 1000 at 10% compound interest per annum compounded annually for 3 years .........................( CASE 2 )
Principal (P) = Rs. 1000
Rate of interest (R) = 10% per annum
Time (n) = 3 years
C.I=P((1+100R)n−1)=1000((1+10010)3−1)=1000((1+101)3−1)=1000((1010+1)3−1)=1000((1011)3−1)=1000×(10001331−1)=1000×(10001331−1000)=1000×1000331=331
C.I = Rs. 331
(S.I =330 < C.I = 331)
(CASE 1) < (CASE 2)
S.I < C.I
So, investment at compound Interest is better.
Q. (8)
Principal (P) = Rs. 400000
Rate of interest = 16% per annum
= 16/2 = 8% per half yearly (R)
Time (n) = 1 year = 2 half years
Amount=P(1+100R)n=400000(1+1008)2=400000(1+252)2=400000(2525+2)2=400000×(2527)2=400000×25×2527×27=400000×625729=640×729=466560
So, they earn Rs. 466560
...................^_^