In a geometric progression, the 5th term is 16 times the first term. Find the 7th term if the first term is 2A128B256C512D1024Answer: A. 128 Read Explanation: nthterm=a(r−1)n/(r−1)nth term =a(r-1)^n/(r-1)nthterm=a(r−1)n/(r−1)firstterm(a)=2first term (a)= 2firstterm(a)=25thterm=a(r−1)5/(r−1)=16a5th term = a(r-1)^5/(r-1)=16a5thterm=a(r−1)5/(r−1)=16a2(r−1)5r−1=16×2\frac{2(r-1)^5}{r-1}=16\times2r−12(r−1)5=16×2(r−1)4=16(r-1)^4=16(r−1)4=16(r−1)4=24(r-1)^4=2^4(r−1)4=24r−1=2r-1=2r−1=2r=2+1=3r=2+1=3r=2+1=37thterm=a(r−1)7/(r−1)7th term = a(r-1)^7/(r-1)7thterm=a(r−1)7/(r−1)=2(3−1)7(3−1)=\frac{2(3-1)^7}{(3-1)}=(3−1)2(3−1)7=2×272=\frac{2\times2^7}{2}=22×27=128=128=128 Read more in App
