1. Five bells tolled together and since then they began to toll at intervals , , , and secs. They will again toll together after
(A) 3 minutes (B) 4 minutes (C) 5 minutes (D) 6 minutes
2. Two pipes can fill a cistern in 20 minutes and 30 minutes respectively. Both pipes being opened, time when the first pipe must be turned off so that cistern may be filled in 10 minutes more will be
(A) 8 minutes (B) 9 minutes (C) 10 minutes (D) 12 minutes
3. B starts from the same place 3 hours after A who runs 4 km. an hour. If B runs km. an hour distance at which B will overtake A will be
(A) 40 Km. (B) 44 Km. (C) 48 Km. (D) 52 Km.