Renee can sew a 25-square-foot quilt in 16 hours thus her rate is: 25/16 ft^2/hr

Genera can sew the same size quilt in 12 hours thus her rate is: 25/12 ft^2/hr

Let x represent the hours they need to sew the quilt together thus their together rate is: 25/x ft^2/hr

26/16 + 25/12 = 25/x

........

click here to see all the equation solution steps

........

x = 6.74 hr

It will take 6.74 hours to sew the quilt together.