Question

in an AP a ratio of 5th and 10 th term is 1:2 and 12 th term is 36 find the AP​

Answer 1

Answer:

in the explanation

Step-by-step explanation:

let the 5 th term be = a + 4d =  x

and the 10 th term be = a + 9d = 2x

∴   (a+4d)/(a+9d) = 1/2

or, 2(a+4d)  = (a+9d)

or,  2a + 8d =  a + 9d     where a = first term & d = common d

or,    2a - a  = 9d - 8d                 d = common difference

or,        a     =     d

∴12 th term is = a + 11d = 36  

∴ d + 11d = 36

or,     12d = 36

or,        d  =  3

∴ a = d = 3

hence the AP is --------- 3,6,9,12,15,18,21,24,27,30,33,36,39................