i think first you must Unification of denominatorsit will 60 for (3,4,5) so you will get
2\5 = 24\60
1\4 = 15\60
1\3 = 20 \60
then you divide each one apart then multiply by total number (3,800)
so :
24\60 * 3800 = 1520
15\60 * 3800 = 950
20 \60 * 3800 = 1267
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note : when you will gather results you will get Approximate number to 3800
i hope i helped