Can you find out which number multiplied by itself will give the output as 12345678987654321?

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

A man died and leaves Rs.10,000 in his will. There are 6 beneficiaries- his 3 sons and their wives. The 3 wives receive Rs.3960 of which Priyanka gets Rs.100 more than Tanu and Neha gets Rs.100 more than Priyanka.
Pramod gets twice as much as his wife, Tushar gets the same as his wife, and Prashant gets 50% more than his wife.

Who is married to whom?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

Replace the question mark with the correct number in below Picture:

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?