an 18 carat gold contains ---

a. 15% impurities

b. 25% impurities

c. 30% impurities

d. 40% impurities

plz answer.....and also giv de reason 4 ur answer!!

 it contains 75 % pure goldddd

 25% because out of 100% element 75% unit is only pure and complete element while the rest consists of impurities.

Carats are indicator of how pure a metal or element like Au, Ag is.

This is because it is very difficult to get real pure gold with absolutely no impurities ...........

yup and pure gold is also not suitable for general purposes. Pure gold is generally used in the manufacture of SIM cards and used in computers