If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

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?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

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

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

A man always keeps a spare tyre in his car. To make full use of all the five tyres, he changes the tyres in a manner that for a distance of 1, 00,000 km, each of them runs the same distance.

Can you calculate the distance travelled by each tyre on that journey?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?