Last week, a candle store received $355.60 for selling 20 candles Small candles sell for $10.98 and large candles sell for $27.98 How many large candles did the store sell?

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Answer 1 · 2016-12-02T21:15:28

The store sold 8 large candles.

First, let's call the small candles the store sells $s$ $s$ and the large candles they sell $l$ $l$ :

Then, from the problem, we know:

$s + l = 20$ $s + l = 20$

and

$s \cdot 10.98 + l \cdot 27.98 = 355.60$ $s*10.98 + l*27.98 = 355.60$

If we solve the first equation for $s$ $s$ we get:

$s + l - l = 20 - l$ $s + l - l = 20 - l$

$s + 0 = 20 - l$ $s + 0 = 20 - l$

$s = 20 - l$ $s = 20 - l$

Now, we can substitute $20 - l$ $20 - l$ for $s$ $s$ in the second equation and solve for $l$ $l$ :

$((20 - l) \cdot 10.98) + 27.98 l = 355.60$ $((20-l)*10.98) + 27.98l = 355.60$

$219.60 - 10.98 l + 27.98 l = 355.60$ $219.60 - 10.98l + 27.98l = 355.60$

$219.60 + 17 l = 355.60$ $219.60 + 17l = 355.60$

$219.60 - 219.60 + 17 l = 355.60 - 219.60$ $219.60 - 219.60 + 17l = 355.60 - 219.60$

$0 + 17 l = 136$ $0 + 17l = 136$

$17 l = 136$ $17l = 136$

$\frac{17 l}{17} = \frac{136}{17}$ $(17l)/17 = 136/17$

$l = 8$ $l = 8$