Question

today each cookie costs 0.75 less than the normal price. pight now if you buy 7 of them it will only cost you 2.80 . writw an equationd to determine the normal price of each cookie(c)​

Answer 1

The normal price of each cookie is $1.15 derived from the equation, c =today price of each cookie + 0.75

Solution:

Given, Today each cookie costs 0.75 less than the normal price.

Right now if you buy 7 of them it will only cost you 2.80

We have to write an equation to determine the normal price of each cookie(c)

And, we are given that, today 7 cookies cost 2.80

Let the cost of one cookie today be “n”

Then we get,

Today 7 cookies ⇒ 2.8

Then, 1 cookie ⇒ n  

By criss cross multiplication we get,

$\begin{array}{l}{7 \times n=2.8 \times 1} \\\\ {\rightarrow 7 n=2.8} \\\\ {\rightarrow n=0.4}\end{array}$

Which means that, each cookie costs $0.4 today

Now, we know that,

normal price of each cookie, c = today price of each cookie + $ 0.75  

c = 0.4 + 0.75

c= 1.15

Hence, the normal cost of each cookie is $1.15 derived from the equation, c = today price of each cookie + 0.75