Question

If in AP 10th term is 23 and 15th term is 33 then find 30th term.

Answer 1

Answer:

30 th term is 63

Step-by-step explanation:

given ,

in an A.P , t₁₀ = 23 &  ------------------------- (1)

                 t₁₅ = 33    -------------------------- (2)

                                  find, t₃₀

using the formula tₙ = a + (n-1)d

(1) =>          a + 9d = 23

(2) =>         a + 14d = 33

(-)              (-)   (-)       (-)    

                      -5d  = -10

=>                       d = 10/5  = 2

substitute d=2 in (1)

=> a + 9(2) = 23

=> a+18  = 23

=> a = 23-18 = 5

so,  t₃₀ = a+29d = 5+29(2)

                          = 5+58

                          = 63

=> the 30 th term is 63