For the average price 2⅔ lb. = 12/6 = 4/8¼ per lb.

Example 34.—Find in Scotch system the resultant and average counts of 36/36 Scotch with 2/40's cotton.

Bringing the cotton to Scotch counts—

20 × 840
= 84 cut,
200

by the rule—

84 × 18
= 14·82 counts, or × 2 = 29·6 average counts.
84 + 18

This rule can be applied twice in succession to find the counts of a three-fold yarn.

Example 35.—Find the counts of 80's, 40's and 20's folded together and give the average counts if they are used separately in a garment, one thread of each.

Taking 80's and 40's the resultant counts of these two is secured by the usual method—

80 × 40 80 × 40 80
==or 26⅔ counts.
80 + 40 120 3