The ratio of the sum of n terms of two A.P 's is (2n+1):(5n+3).find the ratio of their 10th terms.
Answers
Answered by
3
Ratio of sum of n terms of two Ap' s Sn1/Sn2 = (2n+1)/(5n+3)
n/2[2a1+(n-1)d1]/n/2[2a2+(n-1)d2]=(2n+1)/(5n+3)
simplify it u get
[a1+(n-1)d1/2]/[a2+(n-1)d2/2]=(2n+1)/(5n+3)
put n=10 in both sides,we get
[a1+(10-1)d1/2]/[a2+(10-1)d2/2]= (2*10+1)/(5*10+3)
[2a1+9d1]/[2a2+9d2]=21/53
n/2[2a1+(n-1)d1]/n/2[2a2+(n-1)d2]=(2n+1)/(5n+3)
simplify it u get
[a1+(n-1)d1/2]/[a2+(n-1)d2/2]=(2n+1)/(5n+3)
put n=10 in both sides,we get
[a1+(10-1)d1/2]/[a2+(10-1)d2/2]= (2*10+1)/(5*10+3)
[2a1+9d1]/[2a2+9d2]=21/53
Similar questions