Question

At the soup to nuts cafeteria, larry orders two pieces of toast and a bagel, which comes out to $\$1.30$. Curly orders a bagel and a muffin, which comes out to $\$2.50$. Moe orders a piece of toast, two bagels, and three muffins, which comes out to $\$6.95$. How many cents does one bagel cost

Answer 1

Let us take costs of a piece of toast = $t, , one bagel cost=$b and a muffin cost=$m.

Larry

Two pieces of toast and a bagel cost  = $1.30

2t+b=1.30   -------------equation(1)

Let us solve the equation(1) for t in terms of b, because we need to find one bagel cost.

Subtracting b from both sides we get

2t+b-b=1.30-b

2t= 1.30-b

Dividing by 2 on both sides.

2t/2= (1.30-b)/2

t= (1.30-b)/2

Curly

A bagel and a muffin cost = $2.50.

b + m = 2.50 -------------equation(2)

Solving equation for m in terms of b, we get

m= 2.50-b.

Moe

A piece of toast, two bagels, and three muffins cost = $6.95

t + 2b + 3m = 6.95    ......................equation(3).

Substituting t= (1.30-b)/2 and m= 2.50-b in equation (3)

(1.30-b)/2 + 2b + 3(2.50-b) = 6.95 .

Multiplying each term by 2 to get rid 2 from denominator of (1.30-b).

2*(1.30-b)/2 + 2*2b + 2*3(2.50-b) = 2*6.95

1.30-b + 4b + 6(2.50-b) = 13.90.

1.30 - b + 4b  +15 - 6b = 13.90

Combining like terms

-3b +16.30 = 13.90

Subtracting 16.30 from both sides.

-3b +16.30-16.30 = 13.90-16.30.

-3b= -2.4

Dividing both sides by -3.

-3b/-3 = -2.4/-3

b = 0.8

Therefore, cost of one bagel = $0.80.