Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Two friends decide to get together; so they start riding bikes towards each other. They plan to meet halfway. Each is riding at 6 MPH. They live 36 miles apart. One of them has a pet carrier pigeon and it starts flying the instant the friends start traveling. The pigeon flies back and forth at 18 MPH between the 2 friends until the friends meet.

How many miles does the pigeon travel?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

I am an odd number. Take away a letter and I become even. What number am I?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

You are playing as white and given four rooks to checkmate the black king in four moves with the following rules 1. You can place one rook every move and ensure the black king should be in check position.2. After four moves the black king should be in the checkmate position.

Solve the alphametic puzzle by replacing the alphabet with the number.

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In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.