Answer:
FIFO method equivalent units are obtained by adding the beginning WIP and units started and deducting the ending WIP.
The equivalent units under each of the three assumptions are 
Materials Conversion <u>67,800           67,800</u>
Materials Conversion<u>56730           56730</u>
Materials Conversion <u>69060           69060</u>
Explanation:
<u>Assumption 1 : </u>all materials are added at the beginning of the process and conversion is 100% complete
<u>Particulars    Units          % of Completion             Equivalent Units</u>
<u>                                      Materials  Conversion        Materials  Conversion </u>
BWIP       25,200       100              100                   25,200       25,200 
Add 
Units Started 58,800                                            58,800         58,800
Less 
Units Completed 
<u>                    16,200                                               16,200            16,200</u>
<u>Equivalent Units                                                   67,800           67,800</u>
<u />
<u>Assumption 2:</u>
Beginning Inventory is 40% complete as to materials and conversions and ending inventory is complete 75 %as to materials and conversions.
<u>Particulars    Units          % of Completion             Equivalent Units</u>
<u>                                      Materials  Conversion        Materials  Conversion </u>
BWIP       25,200        40              40                   10,080       10,080 
Add 
Units Started 58,800                                             58,800         58,800
Less 
Units Completed 
<u>                    16,200       75                  75               12150            12150</u>
<u>Equivalent Units                                                   56730           56730</u>
<u />
<u>Assumption 3:</u>
Beginning Inventory is 60% complete as to materials and conversions and ending inventory is complete 30 %as to materials and conversions.
<u>Particulars    Units          % of Completion             Equivalent Units</u>
<u>                                      Materials  Conversion        Materials  Conversion </u>
BWIP       25,200        60              60                   15,120       15,120 
Add 
Units Started 58,800                                             58,800         58,800
Less 
Units Completed 
<u>                    16,200       30                  30               4860            4860</u>
<u>Equivalent Units                                                   69060           69060</u>
<u />
FIFO method equivalent units are obtained by adding the beginning WIP and units started and deducting the ending WIP.