If a1,a2,...a50are in GP, then(a1-a3+a5-...+a49)/(a2-a4+a6-...+a50)is equal to
a2/a5
a4/a6
a1/a2
a6/a1
Finding the value of (a1-a3+a5-...+a49)/(a2-a4+a6-...+a50):
Given that a1,a2,...a50 are in GP
Let a be the first time and r be the common ratio
a1=aa2=ara3=ar2an=arn-1(a1-a3+a5-...+a49)/(a2-a4+a6-...+a50)=(a-ar2+ar4+...ar48)/(ar-ar3+ar5+...ar49)=(a-ar2+ar4+...ar48)/r(a-ar2+ar4+....ar48)=1/r=a/ar=a1/a2
Hence, Option (C) is correct.