Contradictions usually mean they go against established rules. Squaring a negative number is one example if it is in math. But just think of anything that goes against what is known.
Ummm this confuses me a bit
That would not be right because 4 times 3 equals 12 and -6 times 3 equals -18.
Answer:
6 2/3 minutes
Step-by-step explanation:
Their rates in "jobs per hour" are ...
(60 min/h)/(15 min/job) = 4 jobs/h
and
(60 min/h)/(12 min/job) = 5 jobs/h
So, their combined rate is ...
(4 jobs/h) + (5 jobs/h) = 9 jobs/h
The time required (in minutes) is ...
(60 min/h)/(9 jobs/h) = (60/9) min = 6 2/3 min
Working together, it will take them 6 2/3 minutes.
