-2
21 = (.12)(x) 21 / .12 = x Answer: 175
12. you're doing multiples of 3 and the tens and ones places are just reversed in the writing- 3 6 9 12 15 18 21=3 6 9 21 51 81 12
To calculate half (1/2) of any number, divide that number by 2.
21
If a progression goes 15 __ 21, then the missing number will dictate how the pattern increases with every number. If the missing number is 18, this means that the numbers go up in threes. The pattern would continue 24, 27, 30, 33...
30
9
23
The Answer is 26
The missing number is 21. This follows the pattern of the Fibonacci sequence where each number is the sum of the two preceding numbers.
22
12 (2x2x3)
10 and 21
75
17
16, 12+15+21 = 48/3 = 16