5 * 124 = 620

Consider the arrangement
A B 140 D E

To maximize A , we need to minimize D & E
minimum value of D = min val of E = 140

140 * 3 = 420

620 - 420 = 200

Now we need to distribute 200 between A & B such that A <= B <= 140

therefore A = B = 200/2 = 100

What is the OA ?

5 pieces of wood

124 = mean
140 = median or the middle value
we need to find the maximum possible value therefore, minimize all the other values

the shortest piece of the wood has to be less than 140, largest has to be greater than 140.

total = 124*5 = 620

x + y + 140 + 140 + 140 = 620

x+y = 620-140*3 = 620-420

x+y = 200

Maximum possible length = 200/2 = 100.