Hello,
Here is the formula:
S.A.=(l+w)×2×h+l×w×2
Then, we just substitute this
S.A=(10+6)×2×4+10×6×2
S.A.=16×2×4+60×2
S.A.=32×4+120
S.A.=128+120
S.A=228 square inches. As a result, the surface area of this rectangular prism is 228 square inches. Hope it help!