Find the simple interest. Assume the rate is an annual rate. Assume 360 days in a year. Principal 1300
Time in Months t=3
Rate r=2 1/2%
Interest

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540