Amir is starting a stamp collection. After 3 weeks he has collected 35 different stamps, and after 9 weeks he has collected 105 different stamps. What is the constant of proportionality in this direct variation?

3/35

Step-by-step explanation:

Here, we want to know the constant of proportionality in this direct variation scenario

Since it is a direct variation, the form we are having would be;

x = ky

where x and y directly vary with each other and k is the constant of proportionality

Now, for the first relation

3 = 35k

for the second

9 = 105k

Thus k would be

3/35 which is the same as 9/105

Kindly note that 9/105 can be reduced to 3/35

So linking the number of weeks to the number of stamps collected, the constant of proportionality is 3/35

the 4th choice is the correct one

step-by-step explanation: