$6/(2/5) = $6*5/2 = $3*5 = $15
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The question is a bit ambiguous. It could be read as "my friend pays 3/5 of a dollar". In that case, the total price is $6.60. As worked above, we assume your $6 paid for 2/5 of the dinner.
The question is a bit ambiguous. It could be read as "my friend pays 3/5 of a dollar". In that case, the total price is $6.60. As worked above, we assume your $6 paid for 2/5 of the dinner.
