Answer:25
Explanation:
1 , 1+3 ,1+3+5 ,1+3+5+7,_
1 , 4 , 9 , 16 ,_
From 1 to 4 there is a difference of 3
From 4 to 9 there is a difference of 5
From 9 to 16 there is a difference of 7
From 16 to x there should be a difference of 9 because all the differences mentioned above are all odd numbers so that is the pattern in the sequence
16+9=25