Question

Adam can clean a room in 3 hours. If his sister Maria helps, they can clean it in 2 2/5 hours. How long will it take Maria to do the job alone?

Answer 1

Adam can clean a room in 3 hours. If his sister Maria helps, they can clean it in 225 hours. How long will it take Maria to do the job alone?
2 2 = 12 Together time, 2 2 , needs to be converted to fraction 555
Adan:3,Maria:x,Total: 5 Clearlystatetimesforeachandtotal,usingxforMaria 12
1+1= 5 Usingreciprocals,addtheindividualtimesgivestotal 3 x 12
1

1(12x) + 1(12x) = 5(12x) 3 x 12
4x+12=5x −4x −4x 12=x It takes Maria 12 hours
Multiply each term by LCD of 12x
Reduce each fraction
Move variables to one side, subtracting 4x Our solution for x



Answer is - 12 hours