How can you make number one disappear by adding something to it?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

In the Mexico City area, there are two Houses H1 and H2. Both H1 and H2 have two children each.
In House H1, The boy plays for Mexico Youth academy and the other child plays baseball.
In House H2, The boy Plays soccer for his school in Mexico and they recently have a newborn.

Can you prove that the probability of House-H1 having a girl child is more than that of House-H2?

Can you find out the missing number in the grid?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Spot 5 differences in two Christmas tree below:

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

On a bright sunny day, two fathers took their son fishing in the lake. Each man and son were able to catch one fish. When they returned to their camp, there were only three fishes in the basket. What happened?

PS: None of the fish were eaten, lost, or thrown back.

Take one out and scratch my head, I am now black but once was red. What am I?

Replace the question mark with the correct number in the below-given picture?