Calculate how many seconds it eill take for 4 bells to toll together again, given that they begin to toll together respectively at the intervals of 5, 8, 11 and 15 seconds. ?  Answers
A) 1310
B) 1320
C) 1322
D) 1323
E) 1312

Rationale: lcm of 5 , 8 , 11 and 15 is 1320 lcm = 1320 answer : b
Answer: B