Question

Bicycle rental on the seawall at the beach cost a mandatory minimum of $5 for the first hour and then $4 for each additional hour. When three or more bikes are rented together, the owner gives a 20% discount on the additional hours. If Marty and his family rent four bicycles, identify the expression which represents the cost.
A) 12.8x + 20x
B) 12.8x + 20
C) 12.8x + 16x
D) 32.80x

Answer 1

Answer:  The correct option is (B) $12.8x+20.$

Step-by-step explanation:  Let, 'x' be the number of hours for which the bicycle is rented except the first hour.

Then, according to the given information, the cost of renting 1 bicycle is given by

$c=4x+5.$

There is a discount of 20% on additional hours 'x' when three or more bikes are rented together.

Since Marty and his family rent four bicycles, so the discount on additional hours for 1 bicycle is given by

$D=20\%\times 4x=\dfrac{20}{100}\times 4x=\dfrac{4}{5}x.$

Therefore, the total cost of renting 4 bicycles is given by

$C=4\left(5+(4x-\dfrac{4}{5}x)\right)=4\left(4+3.2x\right)=12.8x+20.$

Thus, the required expression for the cost is $12.8x+20.$

Option (B) is correct.

Answer 2

Cost = fix cost + hourly cost - discount

Cost = 4* [5 + 4x - 4x(20/100)] = 4*[5 + 4x - 0.8x] = 4*[5 + 3.2x] = 20 + 12.8x

Answer: option B) 12.8x + 20