Sequence X consists of 825 terms, and each term after the first term

Question

Sequence X consists of 825 terms, and each term after the first term is 5 more than the preceding term. What is the 500th term of sequence X?

(1) The 515th term of sequence X is -98

(2) The first term of sequence X is -2668

fmik7894 · Answer

Reference Theory : https://gmatclub.com/forum/math-sequenc ... 01891.html Answer : D

Sasindran · Answer

This is arithmetic progression. 
From Question n=825 d=5.

St1 says a515=-98
We can find a500= a515-15*d = -173

St2 says a1=-2668
We can find a500= a1+499*d= -173

Hence D

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sarbjeetsingh777 · Answer

there are a total of 825 terms 
let "a" be the first term. The series can be written as a, a+5, a+10 . ....
the nth term of the sequence can be written as a+(n-1)5
to find: 500th term = a+499*5
statement1: 515th term = a+514*5 = -98
from this, we can find the value of a and hence the 500th term, hence sufficient
statement2: first term, a=-2668, clearly sufficient

Hence option D

kunalsinghNS · Answer

Question tells that the sequence is in AP hence any nth term is defined as a+(n-1)d, where d = 5 and n = 500. Only missing term is a, which is the first term of the sequence.

1) its tell that 515th term is -98, hence putting this value in a+(n-1)d we can derive the value of a. Sufficient
2) Clearly tells that a = -2668. Sufficient

Answer D

Madhavi1990 · Answer

D. Given: a, a+5, a+10....total number of terms = 825
1) 515th term: -98; through formula a + (n-1)d it is SUFF

2) 1st term: -2668.d= 5. 515th term: SUFF

BrentGMATPrepNow · Answer

Target question :    What is the value of term 500?

Given : Each term after the first term is 5 more than the preceding term.

Statement 1 : Term 515 of sequence X is -98.  
Since each term is 5 more than the preceding term, we know that 
term 514 = -103
term 513 = -108
term 512 = -113
term 511 = -118
etc

As you can see, we COULD keep this pattern going to eventually determine the value of  term 500 
 ASIDE: We'd never actually waste our time finding the value of term 500. We need only recognize that we COULD find the value of term 500 
Since we COULD answer the  target question  with certainty, statement 1 is SUFFICIENT

Statement 2 : term 1 = -2668 
Since each term is 5 more than the preceding term, we know that 
term 2 = -2663
term 3 = -2658
term 4 = -2653
term 5 = -2648
etc
As you can see, we COULD keep this pattern going to eventually determine the value of  term 500 
Since we COULD answer the  target question  with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent

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Sequence X consists of 825 terms, and each term after the first term

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Sequence X consists of 825 terms, and each term after the first term

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