"for other inventory in the same line of business".

This statement signifies that same type of asset was exchanged, thus, lack of commercial substance. It's same line of business, thus, there would be no major change in expected cash flows!

Beam Co. exchanged inventory worth FV $21000 + cash paid $1000 = total worth $22000

Inventory received had FV worth $22000. Thus, FV given = FV received

In case, where boot is paid and exchange lacks commercial substance, no gain is recognized.

Hope this helps!

Then , in that scenario, gain of $1000 would be recognized.

Basis for truck to be recorded = FV of inventory given up 21000 + cash paid 1000 = $22000

Gain = FV of inventory given up - BV of inventory given up = 21000-20000 = $1000

Journal entry :-

DR Truck  22000

CR Inventory  20000

CR Cash  1000

CR Gain  1000