If sequence S has 250 terms, what is the 243r term of S?
1. The 242nd term of S is -494
2.The first term of S is -12 and each term of S after the first term is 2 less than the preceding term
What is the answer and explanation?
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karthikpandian19
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user123321
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1) Since by just knowing a term, we cannot determine another term in a sequence, because we need to know the common difference. hence insufficient.karthikpandian19 wrote:If sequence S has 250 terms, what is the 243r term of S?
1. The 242nd term of S is -494
2.The first term of S is -12 and each term of S after the first term is 2 less than the preceding term
What is the answer and explanation?
2) a = -12
d = -2
so 243rd term = -12+(243-1)*(-2)
hence sufficient.
[spoiler]is it B?[/spoiler]
user123321
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karthikpandian19
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right answer is perfectly Buser123321 wrote:1) Since by just knowing a term, we cannot determine another term in a sequence, because we need to know the common difference. hence insufficient.karthikpandian19 wrote:If sequence S has 250 terms, what is the 243r term of S?
1. The 242nd term of S is -494
2.The first term of S is -12 and each term of S after the first term is 2 less than the preceding term
What is the answer and explanation?
2) a = -12
d = -2
so 243rd term = -12+(243-1)*(-2)
hence sufficient.
[spoiler]is it B?[/spoiler]
user123321
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neelgandham
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If sequence S has 250 terms, what is the 243r term of S?
1. The 242nd term of S is -494.
1. The 242nd term of S is -494.
2.The first term of S is -12 and each term of S after the first term is 2 less than the preceding termIf the sequence is a sequence of ascending numbers and if all the terms in the sequence are integers than 243rd term = -493
If the sequence is a sequence of ascending numbers and if all the terms in the sequence are integers than 243rd term = -495
One can get multiple answers/multiple sequence types.Hence, insufficient.
IMO BFirst term = -12, nth term = -12 - (2*(n-1)) when n = 243, nth term = 12 - (2*(243-1)). Sufficient
Anil Gandham
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bpdulog
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Looks like it's B.
[spoiler]1)[/spoiler] is forcing you to believe a certain pattern exists, when in fact there are many possibilities.
[spoiler]1)[/spoiler] is forcing you to believe a certain pattern exists, when in fact there are many possibilities.
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"Winston tastes good like a cigarette should."
