Prove that the below maths equation is true.

8 + 8 = 91

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

What has one letter and starts with an E?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

Can you count the number of squares in the figure below?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?