Question

Numa PG,dados A1=2 , Q=5 , An= 1250 calcule n.

Answer 1

a1 = 2
q = 5
an = 1250
n ?

1250 = 2 * 5ⁿ⁻¹
5ⁿ⁻¹  = 1250/2 = 625 = 5⁴
n - 1 = 4
n = 4 + 1 = 5 ****