Answer:
Real word Problem:- Jean is working in a pizza shop. She has 60 kg of flour. She has used one-fifth of it for making pizzas. How much flour she used for making pizzas?
Solution:- Quantity of flour she has= 60 kg
The quantity she used in making pizzas=
hence, she used 12 kg of flour for making pizzas.
Here the multiplication of a fraction and a whole number and its answer is between 10 and 15, since 10<12<15.
Given:
The height h of an object after t seconds is
The height of a neighboring 50-foot tall building is modeled by the equation h=50.
The time (t) when the object will be at the same height as the building is found to be t = –2 and t = 5.
To find:
The statement which describes the validity of these solutions.
Solution:
We have,
Here, t is the time in seconds.
For t=-2,
For t=5,
So, the value of h is 50 at t=-2 and t=5.
We know that time is always positive so it cannot be negative value. It means t=-2 is not possible.
The solution t = 5 is the only valid solution to this system since time cannot be negative.
Therefore, the correct option is C.