Hey there! I'm happy to help!
We see that Rosy uses 1/4 of the bottle to wax 2/3 of the car.
We need to 1/3 more to wax the entire car.
1/3 is half of 2/3.
We used 1/4 bottle for 2/3 of the car.
Therefore, we need half of 1/4 bottle for 1/3 more of the car.
1/4×1/2=1/8
We add this to the original 1/4 to see the total amount we used to wax the entire car.
1/4+1/8=3/8
Therefore, Rosy will use 3/8 of the bottle of car wax to wax her entire car.
