2009 · Q7
There are four numbers forming a GP in which the third term is greater than the first by 9 and the second term is greater than the fourth by 18. What is the first term?
Elementary MathematicsStatistics
- A2
- B3
- C– 2
- D– 3
Explanation
ar² = a+9 and ar = ar³+18 give r = −2, a = 3.