 <translate> Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 3 gallons\
Volume of whole = 3 * 40 = 120 gallons. The answer: (C). <yor> Iṣẹ́ tí ẹ̀rọ ìfọntí ṣe ní ìṣẹ́jú kan = 1/15 - (1/20 + 1/24) = - 1/40 Ìwọ̀n ìdìpọ̀ 1/40 = 3 galoni\ Iye ti gbogbo = 3 * 40 = 120 gallons. Ìdáhùn náà ni: (C). 