An airplane takes 5 3/4 hours to reach its destination and 4 1/2 hours to return. If the plane was on the ground for 1 1/4 hours, what was the total time the plane was gone?

My answer is 11 1/2 hours, i just added all three numbers am I right?, or was I just supposed to add the time it took to reach the destination and to return so was i supposed to add the two fractions or am i right?

Yes. 11 1/2 hours is correct.