Answer:
192
Step-by-step explanation:
To find how many phones are expected to be defective, we need to represent the values in a fraction.
x = number of defective phones
Now we can solve this using algebra.
To get the value of x we need to multiply both sides by 8000 to leave x alone.
So around 192 cell phones are expected to be defective out of 8000 phones.
ANSWER
Find out the how much fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
To proof
let us assume that the fluid should be drained and replaced with pure antifreeze be x .
As given
A radiator contains 10 quarts of fluid, 30% of which is antifreeze.
Now write 30% in the decimal form
Now write 60% in the decimal form
After drained and replaced the fluid with pure antifreeze than the quantity becomes = ( 10 - x )
The quantity of antifreeze is
The fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
than the equation becomes
solyving
100x +300 - 30x = 600
70x = 300
x = 4.28 quarts (approx)
Hence 4.28 quarts (approx) fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
Therefore the option (c.) is correct .