it cost 40 dollars for 3.5 grams of special bath salts.... if some body had 20 dollars how many grams should i give them?

Question

i don't really have much to say besides this is a word problem that i got in school and i don't understand it... please help!

Answer 1

This is a problem based on direct proportion 

 

Since 3.5g could be bought for $40

 

We can use the following equation

 

40 K = 3.5

 

K = 3.5 / 40

 

   = 7 / 80

 

USE THIS VALUE AND THE VALUE FOR K TO FIND G THE NUMBER OF GRAMS

 

G = 20 ( 7 / 80 )

 

= 7 / 4

 

= 1.75 grams