What is the percentage of a cloth that should be excluded from 40 metre cloth so that the remaining portion is 7 metre? | WBCS 2022

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What is the percentage of a cloth that
should be excluded from 40 metre cloth
so that the remaining portion is 7 metre? (a) 17.5 (b) 19 (c) 82.5 (d) 81 Correct Answer: c