Correct Answer is: (1) 16
Let final temperature be = θ
Heat taken by ice = m1L + m1c1 Δ θ1
= 5 × 80 + 5 × 1 ( θ – 0)
= 400 + 5θ
Heat given by water at 40°C
= m2c2 Δ θ2 = 20 × 1 × (40 – θ )
= 800 – 20θ
As Heat given = Heat taken
800 – 20θ =400 + 5θ
20θ = 400
θ = 400/25 = 16° C