The number of calories Vivi burns in one hour is 252
If she burns 756 calories in 3 hours
756= 3 hours
x= 1 hour
cross multiply
756= 3x
x= 756/3
= 252
Hence Vivi burns 252 calories in one hour
Please see the link below for more information
https://brainly.com/question/10696498?referrer=searchResults