A watch seller gained 20% by selling a watch for rupees 1260. what was its cost price and if we add gain 30% at what price shoul

Question

-BARSIC- [3]

3 years ago

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A watch seller gained 20% by selling a watch for rupees 1260. what was its cost price and if we add gain 30% at what price shoul

d have it sold

Mathematics

1 answer:

vekshin1 · Answer 1 · 2022-02-26T22:43:47+03:00

Answer:

1365 rupees

Step-by-step explanation:

1. Approach

The easiest method to solve this problem is via the method of proportions. One can use a proportion to find the original price of the watch. Then one can find the price of the watch if the watch had a (30%) mark up, by using a proportion.

2. Find the original price

Remember, the general format of a proportion is the following:

$\frac{part}{total}=\frac{percent}{100}$

The following information is given:

The watch sold for (1260) rupees which is (120%) of the original price. Remember, there was a (20%) gain, meaning that the seller recovered (120%) of the price, in essence, the price of the watch, plus (20%) extra, thus (120%). Substitute these values into the proportion and solve,

$\frac{part}{total}=\frac{percent}{100}$

$\frac{1260}{total}=\frac{120}{100}$

Simplify,

$\frac{1260}{total}=\frac{120}{100}$

$\frac{1260}{total}=\frac{6}{5}$

Cross product,

$\frac{1260}{total}=\frac{6}{5}$

$(5)(1260)=(6)(total)$

Simplify,

$(5)(1260)=(6)(total)$

$6300=6*total$

Inverse operations,

$6300=6*total$

$1050=total$

3. Find the price if the mark up is (30%)

Now, one knows the original price of the watch. Set up a proportion to find the price of the watch if there is a (30%) mark up. Use the same logic to set up this proportion as was used to set up the last one. The (percent) will be (130%) because the new price of the watch is (130%) of the original watch.

$\frac{part}{total}=\frac{percent}{100}$

Substitute,

$\frac{part}{total}=\frac{percent}{100}$

$\frac{part}{1050}=\frac{130}{100}$