B.LET X= THE PART OF THE FLOOR THAT CAN BE TILED IN 1 HOUR. SINCE...

12. b.Let x= the part of the floor that can be tiled in 1 hour. Since Steve can tile a floor in 6 hours, he can

1

tile of the floor in 1 hour. Since Cheryl can tile the same floor in 4 hours, she can tile of the floor

4

6

in 1 hour. Use the equation , where represents the part of the floor they can tile in an

x

6

¹

4

¹

x

12x×

¹

6

12x×

¹

4

12x×

¹

x

hour together. Multiply each term by the LCD = 12x. . The equationsimplifies to 2x+ 3x= 12. 5x= 12. Divide each side by 5 to get hours. Since 0.4 times 60x

¹²

5

2.4minutes equals 24 minutes, the final answer is 2 hours 24 minutes.