P6 Math: Before and After Average Expert (Average Decreased after some left)

The meaning of "Average" is 

"the number that is calculated by adding quantities together and then dividing the total by the number of quantities" 

according to Britannica dictionary.

For this "Before and After" Average question type, the total is not given and the average decreased if some parties were excluded from the count.

This question is very similar to another one published here.(where the average increased instead). More of such "before and after average" questions here.

Such questions are common in P6 Prelim Paper 2.

Calculator usage is allowed.

A group of girls have an average of 66 stickers in their collection.

If 3 girls with an average of 70 stickers stickers were excluded from the group,

the remaining girls will have an average of 64 stickers instead.

How many girls were there in this group?

If the above question is easy, try to do the more challenging question below. 

The question below will randomize with different numbers every hour. 

Copy below question down before making attempt.

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P6 Math: Before and After Average Expert (Average Increased after some left)

Average is about equal sharing. 

When the average is given but not the total number of parties to be shared with, the question becomes more complex.

Such "before and after" average questions will often appear in Paper 2 of P6 Prelim exams.

Calculator usage is allowed.

More of such before and after Average questions here and here.

Class 6C took a Math test recently and the class scored an average of 81 marks.

If the results of 4 students with average of 64 marks are excluded, 

the remaining students will have an average of 83 marks for this test.

How many students are there in class 6C?

If the above question is easy, try to do the more challenging question below. 

The question below will randomize with different numbers every hour. 

Copy below question down before making attempt.

Click  if above box appears blank

P5 Math: Average of 2 groups of items

The topic of Average requires students to find out each fair share.

The question type below provides 2 sub-totals, 
from which, students must be able to derive first the total before they can process the average [ aka fair share ].

Such questions can appear in both paper 1 and 2.

Calculator usage is allowed if in Paper 2.

A group of 3 boys have a total of 17 die-cast toy cars.

Another group of 5 boys have a total of 39 die-cast toy cars.

What is the average number of die-cast toy cars owned by each of these 8 boys?

If the above question is easy, try to do the more challenging question below.

The question below will randomize with different numbers every hour. 

Copy below question down before making attempt.

Click if above box appears blank