GATE 2025 CE (CE1) – Question 33
If the weights retained on the 2.36 mm, 1.18 mm, 600 µm, and 300 µm sieves are 30%, 35%, 15%, and 20%, respectively, of the total weight of an aggregate sample, then the fineness modulus of the sample is __________________ (*rounded off to 2 decimal places*).
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 3.73 to 3.77
Explanation
The fineness modulus is the sum of the cumulative percentages retained on the standard sieves (80, 40, 20, 10, 4.75, 2.36, 1.18 mm, 600, 300 and 150 µm) divided by 100. Nothing is retained above 2.36 mm. The cumulative percentages retained are 30 on 2.36 mm, 65 on 1.18 mm, 80 on 600 µm, 100 on 300 µm and 100 on 150 µm. The sum is 375, so the fineness modulus is 3.75.