Question

Jessica is making cookies and brownies for a bake sale. Her recipe for cookies calls for 1 egg per batch, and her recipe for brownies calls for 2 eggs per batch. If Jessica uses 18 eggs and makes 11 batches, how many batches of cookies and brownies did she make?

Answer 1

Answer:

Number of batches of cookies = 4

Number of batches of brownies = 7

Step-by-step explanation:

Let the number of batches of cookies she made = x

And the number of batches of brownies = y

Total number of batches she made = 11

So the equation representing batches will be,

x + y = 11 ---------(1)

Her recipe for cookies calls for eggs = 1 per batch

So eggs required for x batches of cookies = 1 × x = x

Similarly, her recipe for brownies calls for eggs = 2 per batch

So, eggs required for y batches of brownies = 2y

Total number of eggs required = 18

Therefore, equation will be,

x + 2y = 18 ---------- (2)

Equation (2) minus equation (1)

(x + 2y) - (x + y) = 18 - 11

y = 7

From equation (1),

x + 7 = 11

x = 4

Therefore, number of batches of cookies and brownies she made were 4 and 7.