Answer:
y = 15
Step-by-step explanation:
In a parallelogram, opposite lengths are equal.
So it means that the length (5y - 20) is equal to (2y + 25).
Now that there is only one variable in the equation, we can solve for the variable.
5y - 20 = 2y + 25
5y - 2y = 25 + 20
3y = 35
y = 15
Marked(10)/total = 3/20 (from sample)
total/10 = 20/3 (inverting the above proportion)
total = 10•20/3 = 200/3 ≈ 67
