To get the answer we can use proportion.
30 ------------- 100%
12 --------------x
crossmultiply now
30x=12*100%
30x=1200% /:30 (divide both sides by 30)
x=40% - its the percentage of cars which finished the race.
100%-40%=60% - its the answer

3 0

3 years ago

Read 2 more answers

A group of friends spent 52.50$ on 6 movie tickets. Write an equation to represent the cost, c, per movie ticket, t.

Dovator [93]

Answer: 8.75t = c

Step-by-step explanation: 52.5/6 = 8.75 so 8.75$ per ticket.

5 0

3 years ago

What is the solution set of 2x(x - 1) = 3?

garik1379 [7]

First you must distribute the 2x to the numbers inside the parentheses

(2x * x) + (2x * -1) = 3

$2x^{2}$ - 2x = 3

To make this a quadratic equation you can solve bring the 3 over to the left side of the equation by subtracting it to both sides

$2x^{2}$ - 2x - 3 = 0

Use the quadratic equation to solve this (image of the quadratic equation is below)

Remember that quadratic functions are set up like so:

$ax^{2} +bx +c = 0$

That means that in this equation...

a = 2

b = -2

c = -3

^^^Plug these numbers into the quadratic equation and solve...

$\frac{2+/-\sqrt{(-2)^{2}-4(2)(-3)}}{2(2)}$

$\frac{2 +/-\sqrt{4+24}}{4}$

$\frac{2+/-\sqrt{28} }{4}$

$\frac{2+/-2\sqrt{7} }{4}$

$\frac{1+/-\sqrt{7} }{2}$

Keep in mind that +/- is ±

$\frac{1+\sqrt{7} }{2}$

$\frac{1-\sqrt{7} }{2}$

^^^Exact answers

Approximations:

1.823

-0.823

Hope this helped!

~Just a girl in love with Shawn Mendes

8 0

3 years ago