If the cost 15 rupees for 20 liter , how much rupees for 6000 liter ?

Pls! does anybody know a shortcut for answering these types of questions in the future?

Which statement about the relative areas of δabc and δxyz is true? the area of δabc > the area of δxyz the area of δabc < the area of δxyz the area of δabc = the area of δxyz more information is needed to compare.

Kendra had twice as much money as kareem. kendra later spent $8 and kareem earned $6. by then,the two had the same amount of money. how much money did each have originally?