The 5th term of an AP is -3 and its common difference is -4. The sum of the first 10 terms is (a) 50 (b) -50 (c) 30 (d) -30
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The sum of first 10 terms is -50
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Hey here is your answer.
a5= -3 and d= -4
a5= a+4d
-3=a + 4×(-4)
-3=a-16
a=16-3
so,
a=13
a10=a+9d
a10=13+9×(-4)
a10=13-36
a10= -23.
now we have,
sn =n/2{a+an}
s10=10/2{13+(-23)}
s10=5×(-10)
s10=-50.ans
Hey here is your answer.
a5= -3 and d= -4
a5= a+4d
-3=a + 4×(-4)
-3=a-16
a=16-3
so,
a=13
a10=a+9d
a10=13+9×(-4)
a10=13-36
a10= -23.
now we have,
sn =n/2{a+an}
s10=10/2{13+(-23)}
s10=5×(-10)
s10=-50.ans
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