Let the first term of a geometric sequence be 3/4, and let the second term be 15. What is the smallest n for which the nth term of the sequence is divisible by one million?
An infinite geometric series has common ratio 1/8 and sum 60. What is the first term of the series?
3/4 15 300 6000 120000 2,400,000 48, 000, 000
n = 1 2 3 4 5 6 7
48 million IS evenly divisible by 1,000,000 so n = 7
3/4, 15, 300, 6,000, 120,000, 2,400,000.....etc.
I don't see that any term below 1,000,000 is EVENLY divisible by 1,000,000
Sum =F / (1 - R)
60 =F/ (1 - .125)
F =60 x .875
F=52.50 first term
3/4 15 300 6000 120000 2,400,000 48, 000, 000
n = 1 2 3 4 5 6 7
48 million IS evenly divisible by 1,000,000 so n = 7
For an INFINITE series the sum S
S = a1/ (1-r) where r is the common ratio (1/8)
60 = a1 / (1-1/8)
60 x (7/8) = a1 = 52.5