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

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

P6 Math: Average of information given in table

For P6 exams, the average questions will be more challenging than those in P5 papers.

Questons like these will require students to make use of the information in the table to find the subtotal of each column in order to solve.

Such questions usually appear in Paper 2 P6 Prelims.

Calculator usage is allowed.

The table below show the number of customers whom bought pencils in the bookshop yesterday.

Number of pencils bought by each customer	0	1	2	3	4
Number of customers	0	10	9

Two of the numbers in the table are missing.

The customers bought an average of 2.5 pencils yesterday in the bookshop.

a) What was the total number of pencils bought at the bookshop yesterday?

b) How many customers bought 4 pencils each?

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 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

P6 Math: Average of 3 different numbers

With the average of a certain number of values, it is possible to find their total.

With a known value of two of the numbers, it is possible mathematically to find the third value of the group of 3.

This question type requires first for students to be able to find the total before using logic to deduce and calculate the largest possible value of the 3 numbers.
( while complying with the rules of all being different numbers,etc etc )

Such questions are common in Paper 1 of P6 exams.

Calculator usage is not allowed

The average of 3 different two digit numbers is 29.

What could be the value of the largest possible number?

(FYI, the answer is neither 29 nor 99)

Jim Carrey as the Riddler in Batman Forever (1995 movie)

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: TRUE or FALSE or NOT POSSIBLE TO TELL?

Questions such as these are common in P5 and P6 Paper 1.

Students are required to use arithmetic and logic and knowledge of specific topics such as "average" in order to be able to fill in the boxes with the correct ticks.

Calculator usage is not allowed.

Jennifer, Kate and Lena have an average of 30 hairbands.

Each of them have some but different number of hairbands.

Lena has 50 hairbands.

Put a tick in the correct boxes.

Statements	TRUE	FALSE	NOT POSSIBLE TO TELL
Jennifer has 20 hairbands
Kate & Lena have 90 hairbands altogether

Exquisite Bejeweled Hairband

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: Sharing the Workload Thus Lesser Time Needed

This question looks like an "Average" question
but it is not simply adding together and divided by 2.

When the job is shared, the time taken will always be lesser as the workload will be shared.

Such questions are common in P5 and P6 exams.
Calculator usage is not allowed.

Carol will need 5 hours to paint her bedroom.

If the room was painted by her father, he will only need 2 hours.

If both Carol and her father were to paint together,

how long will it take for them to paint her bedroom?
(Give your answer in hours using fraction in simplest form)

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

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

P6 Math: Lowest Possible Score in an Average of Some

The question below deals with the topic of "Average".
The average of some number of tests is known and the student must find out what is the lowest possible score for one of the tests if the maximum is also known.

Such questions usually appear in P6 Prelims and in Paper 1.

Calculator usage is not allowed.

What is OAS?

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: 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