Question

How much ice must be added to 100 g water at ${30}^0$ C in order to reduce its temperature to ${20}^0$ C?

• A. 10 g
• B. 80 g
• C. 400 g
• D. None of these

Answer 1

The correct option is A 10 g

Let the amount of ice be $x$

$x\times 80+x\times 1\times 20=100\times 1\times 10\Rightarrow 100x=1000\Rightarrow x=10g$