Four sheep farmers, namely Ulma, Vimla, Wilma and Xema rented a pasture, as per the following details: Umla grazed her 24 sheep for 3 months; Vimla grazed her 10 sheep for 5 months; Wilma grazed her 35 sheep for 4 months; and Xema grazed her 21 sheep for 3 months. If Ulma's share of rent is Rs. 720, find the total rent of the pasture?