Question

if 14 term of an ap is 64 and its 54 term is - 16 then the common difference is? a) 3/50 b )-3/50 c)5/2 d)-5/2

Answer 1

As we know that,
An = a+(n-1)d
So, A14 = a+(14-1)d = a+13d = 64............(1)
and,
A54 = a+(54-1)d = a+53d = -16...............(2)
By subtracting equation 1 from 2, we will get
a+53d -a-13d = -16-64
40d = -80
d = -2.
So, Common difference will be -2.

I think options are wrong....
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