How can you make number one disappear by adding something to it?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

What is the centre of gravity?

Below, you can see some coding:
January = 1017
February = 628
March = 1335
April = 145
May = 1353
June = 1064
July = 1074
August = 186

Now deciphering the way it has been coded, can you find out how September will be coded?

When can we add 2 to 11 and get 1 as the correct answer?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

Find the number of squares in the below-given picture.

Replace the question mark with the correct number.

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?