150 decigrams of cotton is used to make a piece of cloth. Find its weight in grams.
A piece of cotton cloth shrinks in water. This represents:
The weight of a piece of wire is directly proportional to its length. A piece of wire is 25 cm long and has a weight of 6 grams. Another piece of the same wire is 30 cm long. Calculate the weight of the 30 cm piece of wire.