Process costing

1) A manufacturing process had no opening work-in-progress and no losses during this period. At the end of the period it had completed 2,200 units and had 340 units unfinished.

The costs per equivalent unit for the period were:

Materials $7.50
Conversion costs $5.80
The unfinished units were 80% complete with respect to materials and 50% complete with respect to conversion costs.

What is the value of the completed output?

answer:

2,200 X ($5.80 + $7.50) = $29,260

2) During March, an organisation that uses process costing incurred process costs of $4,355. There were no unfinished goods at the start of the month, but at the end of the month 250 of the 3,000 products were only 50% complete, and 100 were 75% complete. There were no loses during the month.

Calculate the value of the finished output.

asnwer:

Equivalent units of closing WIP 200 (250 × 50% + 100 × 75%)
Products completed 2650 (3,000 – 250 – 100)
Total equivalent units 2850
Cost per equivalent unit $1.53 (4,355/2,850)
Value of finished output $4,050 ($1.53 × 2,650)

The test I mentioned above and this one are the same as they both asked to calculate finished goods.
The similar test’s but calculated differently, I mean in the above example there is no need to calculate EQUIVALENT UNITS OF CLOSING WIP but in this example, we should calculate. Can you tell me why? what is the difference?

thanks in advance