Carly beat the school record for the 400 meter run by 1.3 seconds. if she ran the race in 55.7 seconds, what was the record

If Carly broke the record by 1.3 seconds and Carly's time was 55.7 the old record would be Carly's time plus 1.3 seconds for the time that Carly broke the record by, so... 57 seconds was the old record

Hmm i believe it would be c