If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

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?

I make two people out of one. What am I?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

There are two beautiful yet remote islands in the South Pacific. The Islanders born on one island always tell the truth, and the Islanders from the other island always lie.
You are on one of the islands and meet three Islanders. You ask the first which island they are from in the most appropriate Polynesian tongue, and he indicates that the other two Islanders are from the same island. You ask the second Islander the same question, and he also indicates that the other two Islanders are from the same island.
Can you guess what the third Islander will answer to the same question?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

Why did Buffon take the goal with him after every Juventus match?