Question

the average of 7 consecutive odd numbers is 45 . find the biggest of all​

Answer 1

Answer:

the biggest number is 51

Answer 2

Answer:

51

Step-by-step explanation:

Let the numbers are a - 5, a - 3, a - 1, a + 1, a + 3, a + 5, a + 7.

Sum = a - 5 + a - 3 + a - 1 + a + 1 + a + 3 + a + 5 + a + 7

       = 7a + 7

Hence, average:

⇒ 45 = (7a + 7)/7

⇒ 45 = 7(a + 1)/7

⇒ 45 = a + 1      ⇒ 45 - 1 = a

⇒ 44 = a

      Hence,

Largest = a + 7 = 44 + 7 = 51

             For sum of number we can use AP as well,

Sum = (7/2)(2a + (7 - 1)2)

        = (7/2)(2a + 12)

        = 7(a + 7)

So,

⇒ 45 = [7(a + 6)}/7

⇒ 45 = a + 6

⇒ 39 = a

   Hence, the largest number = a + (7 - 1)d = 39 + (6)(2)

= 39 + 12 = 51