Weight calculation

This task is about using algebra to solve maths problems.
 
illustration: Three dogs: Kuri, Max and Poppy
Kuri got on some scales with Poppy, and together they weighed 100 kg. Poppy weighed 3 times as much as Kuri.
Here is a statement in algebra describing what happened:
3y + y = 100

Question 2Change answer

a)  How heavy was Poppy?   kg
b)  How heavy was Kuri?  kg
c)  What does the 3y stand for?  

Question 2Change answer

Poppy, Max and Kuri all got on the scales.
d)  Max was half the weight of Kuri. What did Max weigh?   kg
e)  How much would all three dogs weigh together?    kg