On selling an article for Rs 2300, a shopkeeper made a profit of 15 %. find the cost price of the article.

Let the cost price of article be x :

x + x × ( 15/100 ) = 2300

x + x × ( 5 × 3 / 5 × 20 ) = 2300

x + x × ( 3 / 20 ) = 2300

x + ( 3 × x / 20 ) = 2300

x + ( 3x / 20 ) = 2300

( 20x / 20 ) + ( 3x / 20 ) = 2300

20x + 3x / 20 = 2300

23x / 20 = 2300

Multiply both sides by 20

( 23x / 20 ) × 20 = 2300 × 20

23x = 2300 × 20

23x = 23 × 2000

Divide both sides 23

23x ÷ 23 = ( 23 × 2000 ) ÷ 23

x = Rs 2000

b) the dogs need to shift their focus to human scent.