Question

How many terms office series 1+4+16+... Make tha summa 1365

Answer 1

Answer:

6 terms

Step-by-step explanation:

1+4+16+...  & S=1365

We have here GP with 1st term of 1 and common factor 4 and sum of n terms equal to 1365.

Sum of n terms:

Sₙ=a(rⁿ-1)/(r-1), where a=1, r=4

• a(rⁿ-1)/(r-1)=1365
• (4ⁿ-1)/(4-1)=1365
• 4ⁿ-1=1365*3
• 4ⁿ=4095+1
• 4ⁿ=4096
• n=6

Number of terms = 6