What is the next number in this series?

4,12,84,3612....

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

Kareena is older than Bipasha. Bipasha is younger than Karishma and younger than Katrina. Katrina is older than Kareena and Alonso, who are older than Karishma.If Alonso and Kareena are twins, who's oldest?

Which digit occurred maximum times between the number 1 and 1000?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

Count the number of squares in the picture below.

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?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1