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

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

What has many keys but can’t open a single lock?

An old Woman left INR 33,333 to be divided equally among two fathers and two sons and each was to receive INR 11,111.
How was this possible?

Count the number of triangles in the below picture?

What is at the end of a rainbow?

Spot what is wrong here in below Picture?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?