The cost of 40 candy bars is $30 how much does 15 cost

$20

Step-by-step explanation: We first need to figure out how much a single candy is worth. To do that we need to divide 40 candy bars by $30. 40/30 is equal to 4/3 or $1.33 dollars each. Now we multiply 15 by the price of a single candy bar which is 4/3 or 1.33 dollars. 4/3*15 is $20.

answer: 7 x 2/5 = 2.8 hours, is your answer. your welcome! : 3

step-by-step explanation: first work out how long it took to hose 1/7 of the lawn which is 2/5 hours. times that by 7 to get the whole lawn.

sorry i don't know the other answer. i didn't learn what a proportional relationship is.