In the International Journal of Engineering Research & Applications (May-June 2013), structural engineers examined the properties of Portland cement mortar made from rice ash husk. The variables measured in the study included the following. Identify the type (quantitative or qualitative) of each variable.

a. Proportion of cement mix that contains rice ash husk

b. Quantity of sand in the cement mix (grams)

c. Quantity of water in the cement mix (grams)

d. Compressive strength of cement (Newtons per millimeters-squared)

e. Setting time of cement (number of minutes)

f. Type of Portland cement used (Type I, Type II, Type III, Type IV, Type V, White)