Aditya, Bharti and Chetan together finish a job in 6 days and are paid ₹5400 for it. Aditya alone could have finished it in 12 days and Bharti alone in 18 days. Chetan's share of the wages (in ₹) is:

In a day Aditya does 1/12 of the job and Bharti 1/18, while the three together do 1/6. So Chetan does 1/6 − 1/12 − 1/18 = 6/36 − 3/36 − 2/36 = 1/36. Wages follow the work done: 1/12 : 1/18 : 1/36 = 3 : 2 : 1, so Chetan gets $5400\times 1/6=$ ₹900. (Splitting ₹5400 equally gives the trap ₹1800.)