The answer is 25.

Solution:

A = 0 + 1 = 1 B = 1 + 3 = 4 C = 4 + 5 = 9 D = 9 + 7 = 16 then E = 16 + 9 = 25

Could also be,

A = 1^2 = 1

B = 2^2 = 4

C = 3^2 = 9

D = 4^2 = 16

E = 5^2 = 25

Both give E = 25 though so it doesn't really matter how you get there

The gap between two number is odd number like 3, 5,7, 9 like that next number is 16+9=25

simple ans 25

The difference between the increments of the figures is 2 so 16 +9 = 25

a=1x1=1 b=2x2=4 c=3x3=9 d=4x4=16 e=5x5=25

If A x 4 = E B ÷ 4 = E C + 4 = E D - 4 = E A + B + C + D = 100

Challenge What is the value of E ?

If abcde=1 (where a,b,c,d and e are all positive real numbers) then what is the minimum value of a+b+c+d+e?