If 23 pupils did not pass maths, find the value of y. Find the probability of picking up at a random a pupil who like both subjects. A tea girl prepared milk tea in such a way that milk was 20% more than water. If was 12 litre only in the tea, how much tea was prepared?

Based on the visible parts of the Venn diagram and common problem structures, we assume:

• Pupils who passed only Maths: $y$
• Pupils who passed only the other subject (let's call it Science): $y+2$
• Pupils who passed both subjects: $y-2$
• Pupils who passed neither subject: 2 Pupils who did not pass Maths are those who passed only Science and those who passed neither subject. So, the number of pupils who did not pass Maths is $(y+2) + 2$.

We are given that 23 pupils did not pass Maths.

The value of $y$ is $\boxed{19}$.

The number of pupils who like both subjects is represented by $y-2$.
Substitute the value of $y=19$:

The total number of pupils is the sum of all regions in the Venn diagram:

Substitute $y=19$:

The probability is the ratio of pupils who like both subjects to the total number of pupils.

The probability is $\boxed{\frac{17}{59}}$.

Question (Tea Problem):
To find the total amount of tea prepared, we need to calculate the amount of milk and then add it to the amount of water.

Amount of water ($W$) = $12 \text{ litres}$.
Milk ($M$) was 20% more than water, which can be expressed as $M = W + 0.20W = 1.20W$.

The total amount of tea is the sum of the