+0

# geometric sequence

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48
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What is the sum of the geometric sequence 2, 10, 50, ... if there are 7 terms?

Mar 8, 2021

#1
+31195
+1

r = 5

2   + 10  + 50 + 250  + 1250 + 6250  +31250 =...........

Mar 8, 2021
#2
+86
0

GP = 2,10,50,...

Let first term a, no. of terms n and common ratio r.

⇒a = 2

r = 5

n = 7

Sum = $${a(r^n-1) \over (r-1)}$$

= $${2(5^7-1) \over (5-1)}$$

= 39062

Mar 8, 2021