Question 1054865
Let {{{ x }}} = his monthly income
{{{ ( 4/15 )*x + ( 1/2 )*x + ( 1/5 )*x + 400 = x }}}
Multiply both sides by {{{ 30 }}}
{{{ 8x + 15x + 6x + 12000  = 30x }}}
{{{ 30x - 29x = 12000 }}}
{{{ x = 12000 }}}
His monthly income was 12,000 rupees