Question

What is the missing number in '?' - 6,4,8,23,?,385.25

Answer 1

Answer:

84.5

f(n+1) = f(n)  * (n - 0.5)  + n  where f(1) = 6

Step-by-step explanation:

What is the missing number in '?' - 6,4,8,23,?,385.25

6

6 * 0.5   + 1    = 4

4 * 1.5   +  2  = 8

8 * 2.5   +  3  = 23

23 * 3.5  +  4  = 84.5

84.5 * 4.5  + 5 =  385.25

f(n+1) = f(n)  * (n - 0.5)  + n

where f(1) = 6

f(2) = f(1) *(1 -0.5) + 1 = 6*0.5 + 1 = 4

f(3) = f(2)*(2 - 0.5) + 2 = 4*1.5 + 2 = 8

f(4) = f(3)(3 -0.5) + 3 = 8*2.5 + 3 = 23

f(5) = f(4)(4 -0.5) + 4 = 23*3.5 + 4 = 84.5