VIC Reverse Mean

(a)      In a Maths test out of 25, the scores of the 10 boys in the class are 13, 24, 10, 6, 19, 23, 11, 9, 18, and 17.

           What is the average (mean) score of the 10 boys?

(b)      There are 5 girls in the same class. The average score for the girls is 18.

           What is the average score of the 15 pupils in the class?

(c)      One of the girls calculated that she got 68%. What mark out of 25 did she get?

Two dogs have an average weight of 23 kg. The heavier dog weighs 3 times as much as the lighter one. What does the heavier dog weighs?

The mean height of seven pupils is 123 cm. One pupil of height 147 cm leaves the group.

Find the mean height of the remaining six pupils

The average weight of the 11 players in a football team was 90 kg.

When the 2 reserve players join them, the average weight of the 13 players was 88 kg.

What was the average weight of the 2 reserve players?

A class took a test. The mean mark of the 20 boys in the class was 17.4. The mean mark of the 10 girls in the class was 13.8.

(a)      Calculate the mean mark for the whole class.

(b)      In a different test, a teacher calculated that a group of 15 pupils had scored an average of 22 marks (out of 30) on a test. However, the teacher had incorrectly marked one pupil’s test, giving him 10 out of 30 when he really should have got 25 out of 30. What should the correct average be?

A group of friends consists of 4 boys and a certain number of girls. The mean height of the boys is 170 cm and the mean height of the girls is 160 cm. The mean height of the whole group (boys and girls together) is 164 cm. How many girls are in the group?