Question

Question type 16 of 19
Questions left: 1
Five times the 5 th term of an AP is equal to
ten times the 10th term. If the common
difference of the AP is 7, then find its 25th
term
25th term​

Answer 1

Answer:

Given: d = 7

and,  t₅ X 5 = t₁₀ X 10

       5(a+4d) = 10(a+9d)

        5(a+4 X 7) = 10(a+ 9 X 7)

        5 (a+28) = 10(a+63)

         5a + 140 = 10a + 630

         5a - 10a = 630 - 140

           -5a = 490

              a = 490/-5

             a = -98

So, 25th term = a + 24d

                       = -98 + 24(7)

                       = 70

Step-by-step explanation:

Hope it helps :)