I think the answer is 2 but I'm not sure
Two strings are 15 inches and 7 inches long.
You could draw a diagram that has two rulers (that are longer than 12 inches).
Draw a piece of string that is exactly 15 inches on one ruler.
Draw another piece of string on the other ruler at exactly 7 inches.
Then you can find the total length of the two strings by adding 15 and 7 inches.
15 + 7 = 22
The total length of both the strings is 22 inches. You can draw a ruler and a piece of string on it at 22 inches.
To answer this item, we let x be the measure of angle Y. If we say supplement, it is understood that when we sum up the measures of the two angles (angle Y and its supplement) the answer should be 180. Therefore the other angle is 180-x. Going back to the condition given in this item, we will be able to generate an equation,
x = 3(180 - x)
The value of x from the equation is 135. Thus, m∠Y is 135°.
