Answer:
last option is correct answer
Step-by-step explanation:

Answer:75
Step-by-step explanation:
90-15=75
The best estimate would be 121/15 = 8.1
we don't know what the value of "X" is, so therefore, we cannot conclude that it is 15 cm.
For this, let's have:
n represent each number, the number after it is its place in sequence
/ means divide
n1 /2 = n2, etc.