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?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

The more you take me, the more you leave me behind.
Who Am I?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

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?

Look at the picture and find out which square is not linked with any of the other squares.

what does the below math rebus puzzle mean?

What's a single-digit number with no value?