convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.
The coordinates of vortex aβ are (8,4) (-4,2) (4,-,4) the coordinates of vortex bβ are (6,6)(12,-,12)(12,12) the coordinates of vortex cβ are(-2,,12)(4,12)(12,-4)