UPSC 2017 CDS II Math Paper

Days required by 4 goats to graze the field = Days required by 6 sheep to graze the field
Therefore, Efficiency of 4 goats = Efficiency of 6 sheep
⇒ 2 goats = 3 sheep
Number of days taken by 4 goats tograze the field = 50 days
Therefore, number of days taken by2 goats and 3 sheep to graze the field = 50 days