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Bala paid $60.80 for some small and big notebooks. Each small notebook cost $3.40 and each big notebook cost $5.60. He bought 2 more small notebooks than big notebooks. How many big notebooks did Bala buy?​

User Blachniet
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1 Answer

4 votes

Answer:

6 large and 8 small notebooks were purchsed.

Explanation:

Let x stand for the number of big notebooks bought. Let s be the number of small notebooks purchased.

We are told that:

s = x + 2 [He bought 2 more small notebooks than big notebooks]

We also know:

A small notebook costs $3.40, and

Each big notebook costs $5.60

The total amount spent would be:

($5.60x) + ($3.40*s) = $60.80 [The price times the number of notebooks is the amount spent on all x (large) and s (small) notebooks. The sum is the total spent ($60.80)]

We have 2 equations and 2 unknowns (x and s), so we should be able to find an answer using substitution. Lets substitute the first equation into the second by using the definition of s as (x+2).

($5.60x) + ($3.40*s) = $60.80

($5.60x) + ($3.40*(x+2)) = $60.80 [Substituted (x+2) for x]

(5.60x) + ($3.40x + $6.80) = $60.80

$9.00x = $60.80 - $6.80

x = ($54.00/$9.00)

x = 6 large notebooks

Since s = x + 2, we know that 8 small notebooks were purchased.

Large: 6 and Small: 8

CHECK: Do 6 large and 8 small notebooks add to a total cost of $60.80?

Large: 6 * $5.60 = $33.60

Small: 8 * $3.40 = $27.20

Total = $60.80 YES

User Sloane
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