looks like a GP with a = 16, and r = 3/2
sum(7) = a( r^7 - 1)/(r-1)
= 16(2187/128) - 1)/(1/2)
= 32(2059/128)
= 2059/4 or 514.75
how can the answer be 115.75 when the first 4 terms shown already add up to 130 ?
Are you just guessing ?
For the series 16, 24, 36, 54,... find S7.
A) 32.17
B) 115.75
C) 514.75
D) 3906.25
B?
1 answer
2 answers