Mr john spends 1/4 of his monthly salary on the repayment of a housing loan.of the remainder he spends 1/5 on food and the pub bill,and puts aside 1/10 for transport costs .this leaves him with $630 a month.what is his monthly salary?plz show the steps

Monthly Salary = $X.

Spends1/4 * $X = X/4.
Bal. = X-X/4 = 3x/4.

Spends1/5 * 3x/4 = 3x/20
Bal.=3x/4-3x/20 = 15x/20-3x/20=12x/20=
3x/5.

Transportation: 1/10 * 3x/5 = 3x/50
Bal.=3x/5 - 3x/50 = 30x/50-3x/50=27x/50.

27x/50 = 630
27x = 31500
X = $1166.67.