[問題]GWD10-22

[luluhsiao]

If the sequence 1.2.4.8.16.32.....each term after the first is twice the previous term . What is the sum of the 16th 17th and 18th terms in the sequence?

Ans :E 7(2^15)

怎麼算就不是這答案..疑惑??
麻煩大家...

[evelight]

16th+17th+18th
=2^15+2^16+2^17
=2^15(1+2+4)
=7(2^15)

[luluhsiao]

原來就這樣呀....我真ㄉ是太...謝謝啦