I hesitated to add this because it’s poorly worded, ambiguous and the answer could be almost anything. I prefer teasers with a single answer, but there you go.
If you came up with a different answer and can explain how you did it, don’t think you’re wrong. It’s probably just as valid. Feel free to share yours in the comments.
My answer for the first number is 2.
Here’s how I got it.
The generic rule for a number in the sequence is: 2^(n – 1) + 1, where n is the position in the sequence.
Note: The teaser doesn’t specify the position of 17. In this case, it’s fifth.
Position 1: (so n = 1) is 2^(1 – 1) + 1 = 2
Position 2: 2^(2 – 1) + 1 = 3
Position 3: 2^(3 – 1) + 1 = 5
Position 4: 2^(4 – 1) + 1 = 9
Position 5: 2^(5 – 1) + 1 = 17
For the curious, the next 5 numbers of the sequence would be:
An electric train is traveling on a 2000-mile journey from Chicago, IL to Los Angeles, CA. It has 16 cars with a total of 320 passengers. The weather is cloudy and cool, with a warm front approaching from the south. Which direction will the steam blow?
I have wood but no bark, And leaves that don’t fall, I am made up of branches, and come in sizes of all.
I am completely devoured many times, over and over by a worm of a kind. If you want to know the answer of mine, look for the secret that I’ve stored inside.
During lunch hour a group of boys from Mr. Bryant’s homeroom visited a nearby grocery store. One of the five took an apple.
Jim said, “It was Hank or Tom”. Hank said, “Neither Eddie nor I did it.” Tom said, “Both of you are lying.” Don said, “No, one of them is lying, the other is speaking the truth.” Eddie said, “No, Don, that is not true.” When Mr. Bryant was consulted, he said, “Three of these boys are always truthful but two will lie every time.”
Tom took the apple Jim was telling the truth Hank was telling the truth Tom was lying Don was lying Eddie was telling the truth (three telling the truth and two lying)
A delivery truck from the post office is sent to the airport to meet a cargo plane at its planned arrival time. The plane lands ahead of schedule and its contents are brought toward the post office by bicycle. After a half hour, the bicycle meets the truck and the mail is transferred.
The truck returns from the post office 20 minutes early. How early did the plane arrive? (Assume all transactions are instantaneous)
The delivery truck arrived back 20 minutes early, so it would have taken 20 minutes to go from where it met the bicycle to get to the airport and back. Therefore, the bicycle and truck met when the truck was 10 minutes from the airport. Adding those 10 minutes to the 30 minutes the truck had already driven to meet the bicycle means the plane arrived 40 minutes ahead of schedule.