it contains puzzles of logical thinking, logical reasoning, numerical ability, aptitude.
27 also possible because in counter clockwise21, 23, 25, 27and clock wise 27, 30, 33, 36
nice answer.yeah,your answer is also correct in another way. keep trying and post different answers on different questions
19 also possible25-4=2127+6=3323-4=1930+6=36
y cant 15, 36+15=51,52,53,54