Answer:
$2.67
Explanation:
Let the price of a cup of regular coffee be $x. Therefore, the price of a cup of mocha would be $(x+1).
Total price = (3 x $x ) + (4 x $(x+1) ) = $(7x + 4)
7x + 4 = 15.69
7x = 11.69
x = 1.67
Price of one cup of mocha = $1.67 + 1 = $2.67