A steam engine intakes 50 g of steam at 100$^\circC per minute and cools it down to 20^\circC. If latent heat of vaporization of steam is 540 cal g-1, then the heat rejected by the steam engine per minute is __________ \times 103 cal.
(Given : specific heat capacity of water : 1 cal g-1 ^\circC-$1)
Choose the correct answer: