If →a=^i+^j+^k,→b=2^i−4^k,→c=^i+λ^j+3^k are co-planar then λ is?
Find the value of λ which will make the vectors →a,→b and →c coplanar, where →a=2^i−^j+^k,→b=^i+2^j−3^k and →c=3^i−λ^j+5^k .