Question

Calculate the count of the threefold cotton yarn composed of 20s, 15s and 12s singles.

• A. 10s
• B. 60s
• C. 15s
• D. 5s

Hint:

For folded yarn: use reciprocal addition method. Then multiply by number of plies for resultant count.

Answer 1

The Correct Option is A

Step 1: Calculate the equivalent count of folded yarn.
The reciprocal of the resultant count of folded yarn equals the sum of the reciprocals of the component counts:
\[\frac{1}{N} = \frac{1}{N_1} + \frac{1}{N_2} + \frac{1}{N_3}\] Step 2: Input the given values.
\[\frac{1}{N} = \frac{1}{20} + \frac{1}{15} + \frac{1}{12}\] \[\frac{1}{N} = 0.05 + 0.0667 + 0.0833 = 0.20\] \[N = \frac{1}{0.20} = 5\] Step 3: Account for threefold yarn.
Because the yarn is threefold, the count of folded yarn = 5s × 2 = 10s.
Step 4: Result.
Therefore, the count of the threefold yarn is 10s.