Pls do its 3rd question

Solution : Total work = LCM (10, 12, 15) = 60 unit Speed of A = \frac{60}{10} unit / days = 6 unit / days Speed of B = \frac{60}{12} unit / days = 5 unit / days Speed of C = \frac{60}{15} unit / days = 4 unit / days If all work together, they will do (6 + 5 + 4) unit / day = 15 unit / day Total time when they work together = \frac{60}{15} = 4 days A will do 6 \times 4 = 24 unit i . e ., \frac{24}{60} = \frac{2}{5} of work B will do 5 \times 4 = 20 unit i . e ., \frac{20}{60} = \frac{1}{3} of work C will do 4 \times 4 = 16 unit i . e ., \frac{16}{60} = \frac{4}{15} of work