Question

Alexa has 12 1/2 cups of dog food . She feeds her dog 1 1/4 cups every day. Write an equation to represent the number of days, d, of the dog food lasts. then solve your equation to find the number of days the dog food lasts?

Answer 1

Answer: 10 days

Let the total number of food be x

Let the number of days be d

Let the number of cups she feeds the dog everyday be y

The equation becomes

The total number of cups of dog food = Number of cups of dog food each day x the number of days

X = y x d

X = yd ------------ Equation

Since, the total number cups of dog food is 12 1/2 and she feeds her dog 1 1/4 cups everyday

Let X = 12 1/2

y = 1 1/4

Firstly, convert the mixed fractions into improper fractions

12 1/2 = 2 x 12 + 1 / 2

= 24 + 1 / 2

x= 25 / 2

1 1/4 = 1 x 4 + 1 / 4

= 4 + 1/4

y= 5/4

To calculate the number of days the food will last, we will be using the above expression

y = xd

25/2 = 5/4 x d

25/2 = 5d/4

Introduce cross multiplication

5d x 2 = 25 x 4

10d = 100

Divide both sides by 10

10d/10 = 100/10

d = 100/10

d = 10 days

The answer is 10 days