GATE 2025 MN – Question 59
A vertical core log begins at590 mRL. Sequential(length m,grade%) values are(3,40),(3,42),(2,41),(3,43),(2,42),(3,41),(3,44). Composite the interval5 m above and below580 mRL. Find grade to one decimal.
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Correct answer: 41.0 to 42.0
Explanation
The target elevations585–575 mRL correspond to depths5–15 m. They include1 m of core2,2 m of core3,3 m of core4,2 m of core5 and2 m of core6. Length-weighted grade is(1×42+2×41+3×43+2×42+2×41)/10=41.9%. Partial cores at the boundaries must be clipped.