If both the sequences x, a1, a2, y and x, b1, b2, z are in A.P. and it is given that y > x and z < x, then which of the following values can (a1-a2)(b1-b2) possibly take?
Explanation:
The two given sequences in AP are:
x, a1, a2, y and x, b1, b2, z.
Additionally, it is given that : y > x and z < x.
Hence the common difference is not zero for both the series :
Since y > x the common difference is positive for the first series. (Considering the common difference to be d1)
Similarly z < x the common difference is negative for the given series. (Considering the common difference to be d2)
Now for the given value:
(a1-a2)(b1-b2)
The value of a1 - a2 is negative and b1 - b2 is positive.
Hence the value of (a1-a2)(b1-b2) takes a negative value.
The only possible option is -3.
The answer is option C.
» Your doubt will be displayed only after approval.