Question

The ratio of the percentage of alumina to that of oxide of iron in the cement should not be less than ________

(a) 0.24

(b) 0.39

(c) 0.66

(d) 0.79

This question was posed to me in an online interview.

I'm obligated to ask this question of Plain and Reinforced in chapter Miscellaneous Materials, Plain and Reinforced Cement Concrete of Construction & Building Materials

Answer 1

Right answer is (c) 0.66

The best I can explain: The ratio of the percentage of alumina to that of oxide of iron in the cement should not be less than 0.66. However, the ratio of the percentage of lime to those of iron oxide, alumina and silica should not be greater than 1.02.