Math

   A family spends 20% of its monthly income on food, 23% on rent, and 42% on other expenses and saves the balance.     

   If the family saves $360 per month, what is its monthly income?     

   20% + 23% + 42% = 85%     

   100% – 85% = 15% saved     

   15% • MI  = $360     

    0.15 • MI = $360     —>     MI  =  $360 / 0.15     

                                              MI  =  $2400     

   .