length of Jim's backyard , L = 15 5/6 = 95/6 yards
width of Jim's backyard , B = 10 2/5 = 52/5 yards
so, area of rectangular backyard = L × B
= 95/6 × 52/5
= (95 × 52)/30
= 494/3 yard²
now, Jim buys sod of length 1 1/3 = 4/3 yards and width = 1 1/3 yards = 4/3 yards .
so, area of rectangular sod = length × width
= 4/3 × 4/3 = 16/9 yard²
number of sod = area of backyard/area of sod
= (494/3)/(16/9)
= 494 × 3/16
= 92.625 ≈ 93
93 pieces of sod will Jim need to buy to cover his backyard.