A Principal amounts to ₹ 944 in 3 yr and to ₹ 1040 in 5 yr, each sum being invested at the same simple interest. The principal was

By formula, P = (A₂T₁ - A₁T₂) / (T₁ - T₂)
Here, A₁ = ₹ 944, T₁ = 3
A₂ = ₹ 1040, T₂ = 5
∴ P = [(1040 x 3) - (944 x 5)] / (3 - 5)
= (3120 - 4720) / (-2)
= (-1600) / (-2)
= ₹ 800
∴ Principal = ₹ 800