If a x 4 = e b / 4 = e c + 4 = e d - 4 = e and a+b+c+d = 100 then what is value of 'e'

I answered this question a while back.

The value of "e" is 16.

a x 4 = e
b / 4 = e
c + 4 = 3
d - 4 = e

a + b + c + d = 100

a x 4 = e
a = e/4

b / 4 = e
b = 4e

c + 4 = e
c = e - 4

d - 4 = e
d = e + 4

e/4 + 4e + e - 4 + e + 4 = 100
e/4 + 4e + 2e = 100
e/4 + 6e = 100
e(1/4 + 6) = 100
e (1/4 + 6*4/4) = 100
e (1/4 + 24/4) = 100
e (25/4) = 100
e = 100 ÷ 25/4
e = 100 x 4/25
e = 400 / 25
e = 16

TO CHECK:

a = e/4    ⇒ 16/4    ⇒ a =   4
b = 4e     ⇒   4*16  ⇒ b = 64
c = e - 4  ⇒ 16 - 4  ⇒ c = 12
d = e + 4 ⇒ 16 + 4 ⇒ d = 20

a + b + c + d = 100
4 + 64 + 12 + 20 = 100
100 = 100