math
posted by chris .
In a particular house,the bedrooms take up 1/3 of the total floor area, and the living room takes up another 1/5.If the rest of the house has an area of 700 square feet,find the area of the living room and area devoted to bedrooms.

first find the total area, call it t
1/3 t + 1/5 t = 5/15 t + 3/15 t = 8/15 t
so the rest is 15/15 t  8/15 t = 7/15 t
and we know 7/15 t = 700
so
t = 700 * 15 /7 = 1500 ft^2
bedrooms = 1500/3
and
living room = 1500/5