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.

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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.

Click  if above box appears blank

P5/P6 Math: Average: Before and After (Advanced)

The question below deals with the topic of "Average",
with the before and after average known
(old average vs new average). 

This question does not provide the number of parties involved at first or at the end.
It only provides the difference between the 2 unknowns.

Such questions appears in P5 SA2 Paper 2 and P6 Paper 2.
Calculator usage is allowed.

Brenda has a collection of dresses.
The average cost of her dresses were $145.

After she bought 2 new dresses at $155 each,

the average costs of all her dresses became $147.

How many dresses did Brenda have in her collection at the end?

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

Click here to register for Mr Neo's class

P6 Math: Average: Before and After (Advance)

The question below deals with the topic of "Average".
Each of the 2 groups' average is known and the average of both groups is also given.

However the exact number of the parties in one of the groups was not provided.

Such questions appears in P6 mid year and prelims.
Calculator usage is allowed.

15 girls spent an average of $30 on stationery.

A group of boys spent an average of $22 on stationery.

Both the boys and girls spent an average of $25 on stationery.

How many children were there altogether?

How pencils are made at the factory?

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

Click here to register for Mr Neo's class

P5/P6 Math: Average Difference if Only One Changed

An average score of a group of students is given.

If one of the student's score increases or decreases by a certain value, the average score changes accordingly.

Such questions are common in Paper 1 of P5 and P6 exams.

Calculator usage is not allowed.

After a Science Test, the average score of a group of students was 83.

Due to an error in marking, one of the students scored 68 instead of 88.

The new average of the group became 82 because of the adjustment.

How many students were there in the class?

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