Question

30 of a number when subtracted from 91 gives the number itself

Answer 1

let number be x
the equation will be
(30*x)-91=x
30x-91=x
30x-x=91
29x=91
x=91/29

Answer 2

Let the number be x

According to the question
91 - 30x = x
91 = x + 30x
31x = 91
x = 91/31
x =2.93