To determine the difference between the number of pounds of flour used than pounds of scones, we simply have to subtract 2/7 from 3/5.
n = 3/5 - 2/7
To answer, first, make the denominator 35 for each of the fraction since 35 is the least common multiple of 5 and 7. The expression now becomes,
n = 21/35 - 10/35
Simplifying,
n = 11/35
Answer: 11/35 lbs.