Sequence

[selango]

In the sequence S of numbers,each term after the first two terms is the sum of two immediately preceding terms.
what is the 5th term of S?

1.The 6th term of S minus the 4th term equals 5.

2.The 6th term of plus the 7th term equals 21.


OA later

[gig92]

1.The 6th term of S minus the 4th term equals 5.

i.e S6 = S5+S4 (from question as given)
thus S6 - S4 = S5 = 5

A) sufficient

2.The 6th term of plus the 7th term equals 21.

It gives no value of any term in the sequence. Therefore impossible to determine S5.
Not sufficient.

[outreach]

s5?

is it A?
1

s6=s5+s4
s4=s3+s2

s6-s4=5
s5+s4-s4=5
s5=5

suff

2
s6=s5+s4
s7=s6+s5

s6+s7=21
s6+s6+s5=21(2 unknown variables)
unsuff

In the sequence S of numbers,each term after the first two terms is the sum of two immediately preceding terms.
what is the 5th term of S?

1.The 6th term of S minus the 4th term equals 5.

2.The 6th term of plus the 7th term equals 21.


OA later

[selango]

OA A