1 mile = 5280 ft.....so 1/3 of a mile is : 1/3 * 5280 = 5280/3 = 1760 ft
and the store sells yarn in sets of 340 ft...
1760/340 = 5.17.....so Shanice would need 6 full sets of yarn......she would actually need a little over 5 sets but since they dont sell half a set, u would round it up to 6 sets