A) (a) \[-46\]
B) (b)\[-76\]
C) (c) \[-80\]
D) (d) \[-70\]
Correct Answer: B
Solution :
[b] and [c] 1st term, \[a=20\] Common difference, \[d=-4\] Last term \[=-176\] \[\therefore {{t}_{n}}=0+\left( n-10 \right).d\] \[176=20+\left( n-1 \right)\left( -4 \right)\] \[(n-1)=\frac{-176-20}{-4}=\frac{196}{4}=49\] n=50 \[\therefore \]There are two middle term 8. So, 25th and 26th term are middle term of the given sequence \[{{t}_{25}}=a+(n-1).d=20+24(-4)\] \[=20+\left( -96 \right)=-76\] \[{{t}_{26}}=20+25\left( -4 \right)\] \[=20-100=-80\]. Hence, option [B] & [C] be correct.You need to login to perform this action.
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