Question
X and Y can complete a certain work in 45 days and 60
days, respectively. They started the work together but X left after some days and Y alone completed the remaining work in 39 days. For how many days did X work?Solution
LCM of 45 and 60 = 180(total work) Efficiency of X = 180/45 = 4 units/day Efficiency of Y = 180/60 = 3 units/day Effective efficiency = 4 + 3 = 7 Let X left after a day, So, a x 7 + 39 x 3 = 180 7a+117 = 180 7a =180-117 Â 7a = 63 Â a = 9 So, after 9 days X left. X worked for 9 days.
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