Question 850485
4/7=12/21 
3/7=9/21
for all three to have 1/3 then they will each have 7/21
so we take 2/21 from Mrs Bryn and 5/21 from Mrs Jacobs for Mrs Smay
They will each have 7/21 
the 21 K will go as follows.
Mrs Bryn will get 6 k and Mrs Jacobs will get 15 k of the 21 k
2/5=6/15