Answer:

Step-by-step explanation:
GIVEN: Catherine sells cupcakes c for
each, The ingredients for each cupcake cost her
, and the sum of all her other expenses is
.
TO FIND: Equation to represent Catherine's profit from selling cupcakes.
SOLUTION:
Cost of ingredients for each cupcake 
sum of all other expenses 
Selling price of each cupcake 
Total cupcakes sold 
Now,
As we know that 
putting values,


Hence the equation to represent Catherine's profit (p) from selling cupcakes for one month Catherine sells is 
10 students averaged 80, so the sum of their scores was (10 x 80) = 800
20 students averaged 89, so the sum of their scores was (20 x 89) = 1,780
All together, the sum of all 30 scores was (800 + 1,780) = 2,580
30 students totaled 2,580, so their average was (2,580 / 30) = <em> 86</em> .
I am unable to solve this problem.
Would it be 5 ? i’m sorry i’m not very sure.