REmember that to create the perpendicular line segment to the segment EF you just have ot adjust the compass to three quarters and draw semi circular segments from points E and "F" that would intersect with eachother and from there to the other side of the segment you draw a line fomr the two points where the semi circles intersect with eachother. so you only need one adjustment to the compass.
First find the price of one pound.
11.94÷6=1.99
Once you find the price of 1 pound.
You multiply the price of one pound 8 times.
1.99×8=15.92
Hope it helps!