1. The half-life a radioactive material is 3 weeks. Determine the mass of 500 mg of the material that is still radioactive after 12 weeks. Show all working out.

They need to admit 43 more cars to make at least $500

Solution:

Given, A drive in theater charges $3.50 per car,  

The drive in already admitted 100 cars,  

Then, money collected until now is $ 3.50 x 100 = $ 350  

We have to solve an inequality to find the number of cars the drive in needs to admit to make atleast 500$

Now, let the number of cars need to be admitted be "n"

Then, inequality is:

collected amount + needed amount ≥ $ 500  

$ 350 + $ 3.50 x n ≥ $ 500

350 + 3.5n ≥ 500

3.5n ≥ 500 – 350  

On solving, we get

3.5n ≥ 150  

n ≥ 42.857

As number of cars can’t be fractions, n = 43

Hence, they need to admit 43 more cars to make at least $500