If 21x = 79x, what is the value of x?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

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

What's a single-digit number with no value?

Can you solve below mathematical equation?

2^1234 - 2^1233

A man always keeps a spare tyre in his car. To make full use of all the five tyres, he changes the tyres in a manner that for a distance of 1, 00,000 km, each of them runs the same distance.

Can you calculate the distance travelled by each tyre on that journey?

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I