A sack of rice, which is 50 kilograms,  costs $50. If David sells it for $1.20 per kilogram, how much will be his profit?
David's revenue for the 50 kilograms of rice is $1.20 x 50 = $<<1.20*50=60>>60.
So, his profit is $60 - $50 = $<<60-50=10>>10.
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