A jeweller has arranged his gems based on the cut and colour of the gem:
Cuts - triangular , rectangular , and octagonal
Colours - amethysts , emeralds , and rubies
How many of the gems are rubies?
How many of the gems are triangular?
How many of the gems are both rubies and triangular?
A jeweller has arranged his gems based on the cut and colour of the gem:
Cuts - triangular , rectangular , and octagonal
Colours - amethysts , emeralds , and rubies
A student creates the following diagram of their favourite animals.
A group of students were asked about their siblings. The two categories show if they have at least one brother, and if they have at least one sister.