Question

which term of an AP is 14 whose first term is -6 and common difference is 1.25​

Answer 1

a = -6

d = 1.25

tn = 14

t = ?

tn = a + (n - 1) d

14 = -6 + (n - 1) 1.25

14 = -6 + 1.25n - 1.25

14 = 1.25n - 7.25

14 + 7.25 = 1.25n

21.25 = 1.25n

n = 21.25/1.25

n = 7