Question

Find fourthterm from the end in an A.P are -11,-8,-5,...,49.

Answer 1

Just rearrange it
49,...,-5, - 8, - 11
Now a = 49
d = - 8-(-5) = - 8 + 5= - 3
Subsitute these value in
a4 = a + (n-1)d
= 49 + (4-1)(-3)
= 49 - 9
= 40