Question

A soil is considered as coarse grained, if it retains more than ___________ in a sieve.

(a) 90% of the soil

(b) 70% of the soil

(c) 50% of the soil

(d) 20% of the soil

This question was addressed to me in an interview for job.

Origin of the question is Unified Soil Classification topic in chapter Classification of Soils of Geotechnical Engineering I

Answer 1

Correct answer is (c) 50% of the soil

Easy explanation: If more than 50 % of the soil is retained on a NO.200 US sieve (0.075), it is designated as coarse grained soil.