If the sum of an infinite GP is 10 and the common ratio is 1/3, what is the firs

Practice Questions

Q1
If the sum of an infinite GP is 10 and the common ratio is 1/3, what is the first term?
  1. 15
  2. 20
  3. 30
  4. 25

Questions & Step-by-Step Solutions

If the sum of an infinite GP is 10 and the common ratio is 1/3, what is the first term?
  • Step 1: Understand that we are dealing with an infinite geometric progression (GP) where the sum is given by the formula S = a / (1 - r).
  • Step 2: Identify the values given in the problem. We know the sum S = 10 and the common ratio r = 1/3.
  • Step 3: Substitute the known values into the formula: 10 = a / (1 - 1/3).
  • Step 4: Calculate (1 - 1/3). This simplifies to (2/3).
  • Step 5: Now rewrite the equation: 10 = a / (2/3).
  • Step 6: To solve for a, multiply both sides of the equation by (2/3): a = 10 * (2/3).
  • Step 7: Calculate 10 * (2/3). This gives a = 20.
  • Geometric Progression (GP) – Understanding the formula for the sum of an infinite geometric series and how to manipulate it to find the first term.
  • Common Ratio – Recognizing the significance of the common ratio in determining the behavior of the series.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely