That depends on your height, age and gender. The best thing to do is to use a BMI (Body Mass Index) calculator that takes these factors into account to calculate whether you are a healthy weight for your age. There are a number of decent ones available online.
you should weigh 105-115
A school backpack should weigh less then 15 % of your body weight.
87-223
if your already 15 a lot i say 100 and under
It should weigh between 11-15 lbs.
It depends. I am 15 and i used to weigh 109 pounds (before school). But most of my friends are much heavier and weigh 155+ pounds.
170 or 175
about 15 pounds
about 70-90kilograms
What_are_some_frequently_asked_nutrition_questions
From 15-20 pounds.
to be skinny, you should weigh anywhere from 110-115 pounds.