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

Chocolate costs 6 rupees and a Toy costs 5 rupees. If you have 32 rupees in total, how many chocolates and how many Toys can be purchased with that amount?

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

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

Using Only Five 5's and any mathematical operator make sum as 37

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.

Can you calculate the total number of cans before distribution?

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