Answer:
B) 30
Step-by-step explanation:
The difference between 87 and 72 is 15, the difference between 72 and 66 is 6, the difference between 66 and 51 jumps back to 15 again and the difference between 51 and 45 jumps to 6 again. This shows that the difference between the numbers are first 15,then 6 then 15 then 6...and so on. Since tue latest difference is 6, the next difference between 45 and the next number would be 15.
Let the number be x.
45-x = 15
45 = 15+x
Isolate the x.
45-15 = x
Find x.
x = 30
Thus, the next number is 30.
