Hey there!
To figure this out, find the time it would take for 1 lb by dividing 150 by 4.
150 / 4 = 37.5
It takes 37 and a half minutes to cook 1 lb.
Now, multiply that by 5, to find out how many 5 lb would be.
37.5 * 5 = 187.5
It takes 187 and a half minutes to cook.
Hope this helps!