2.25 - 1 = 1.25
3.75 -2.25 = 1.5
5.5 - 3.75 = 1.75
7.5 - 5.5 = 2
9.75 -7.5 = 2.25
x - 9.75 = ?
Looking at the pattern, we see that each time we subtract 2 consecutive numbers (going from the smallest to largest) the difference increase by 0.25
So x - 9.75 = 2.5
We solve for x and get: x = 2.5 + 9.75 = 12.25
Therefore the number that replaces the question mark is 12.25
RE: Maths Brain Teasers 63:: Can You Complete The Sequence???