The total cost to buy one bed and one sofa is $1,530. A bed

costs twice as much as a sofa. A wardrobe costs three times as

much as a sofa. If the shopkeeper sold 4 beds and 2

wardrobes today, how much money did he make?

By selling 4 beds and 2 wardrobes, the shopkeeper earns $7140.

Step-by-step explanation:

Here, Let the cost of 1 sofa = $m

Cost of 1 bed + 1 sofa = $1530

⇒Cost of 1 bed = $1530 - $m = 1530 - m

Also, Cost of bed = 2 x Cost of Sofa

⇒ 1530 - m = 2 m

or, 3 m = 1530

⇒ m = 1530/3 = 510

Hence, the cost of 1 sofa = $510

Cost of wardrobe = 3 x Cost of Sofa = 3 ($m)

= 3 x ($510) = $1530

So, from above equations:

Cost of 1 sofa = $510

Cost of 1 bed = $1530 - m = $1530 - $510 = $1020

Cost of 1 wardrobe = $1530

Now, Total cost of 4 beds + 2 wardrobes

= 4 (Cost of 1 bed) + 2 (cost of 1 wardrobe)

= 4 ($1020) + 2 (1530) = 4080 + 3060

= $7140

Hence by selling 4 beds and 2 wardrobes, the shopkeeper earns $7140.