Answer:
31465 ways
Step-by-step explanation:
Given data
Let us apply the combination formula
nCr = n! / r! * (n - r)!
n= 31
r= 4
substitute
= 31!/4!(31-4)!
= 31!/4!(27)!
= 31*30*29*28*27!/ 4!(27)!
= 31*30*29*28/4!
=31*30*29*28/4*3*2*1
=755160/24
=31465 ways
Hence there are 31465 possible ways to rank it
We will check if y and 60cm are parallel.
If the lengths 28cm, 56cm and 15cm, 30cm are in proportion, then y and the segment 60cm are parallel.

OK. We know: y and 60cm are parallel. Therefore we have equation:

<h3>Answer: y = 90 cm.</h3>