Q4 of 167 Page 19

Insert six A.M.s between 15 and - 13.

Let A1, A2, A3, A4, A5, A6 be the 7 AM Between 15 And - 13


Then, 15, A1, A2, A3, A4, A5, A6, - 13 are in AP


We know,


An = a + (n - 1)d


A8 = - 13 = 15 + (8 - 1)d


d = -4


Hence,


A1 = a + d = 15 - 4 = 11


A2 = A1 + d = 11 - 4 = 7


A3 = A2 + d = 7 - 4 = 3


A4 = A3 + d = 3 - 4 = -1


A5 = A4 + d = -1 - 4 = -5


A6 = A5 + d = -5 - 4 = -9


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