Question
The third term of a geometric series is 24 and the fourth term is 36. Determine the sum of the first 10 terms. Express your answers as an exact fraction.
Answers
Steve
T4 = T3*r, so r = 36/24 = 3/2
T3 = ar^2, so 24 = a(9/4), so a=32/3
S10 = 32/3 * (1-(3/2)^10)/(1 - 3/2) = 58025/48
seems clumsy, so better check my math.
T3 = ar^2, so 24 = a(9/4), so a=32/3
S10 = 32/3 * (1-(3/2)^10)/(1 - 3/2) = 58025/48
seems clumsy, so better check my math.