P5 Maths: Mean (Basics) (Paper 3 (challenge))

2026-11-15

Tutor Prep Guide · Using the mean as total over count in all three directions, rebuilding totals and missing items, changes after adding or removing data, combining groups, weighted means and diagnosing common slips

Paper 3 (challenge): ten mean questions on computing the mean, rebuilding totals and combining groups, with answers and one-line notes.

Direct answers　Level: P5 maths; format: computing the mean, rebuilding totals and missing items, adding or removing data, combining groups and weighted means.

01　Paper details (check answers afterwards)

Item	Detail
Questions	10
Suggested time	20
Difficulty mix	Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1
Chapter	Chapter: P5 Maths: Mean (Basics)
Level	P5

02　Questions (10 items)

FoundationGroup A has 5 students averaging 60 and group B has 4 averaging 69; find the combined mean.
FoundationMaths scores 90 with weight 3 and English 80 with weight 2; find the weighted mean.
FoundationFifteen numbers have a mean of 24; find their total.
IntermediateTwelve numbers average 18; one value changes from 30 to 18; find the new mean.
IntermediateSix numbers average 25; after one is removed the remaining five average 23; find the removed number.
IntermediateThree tests average 84; what score in the fourth test gives a mean of 86?
ChallengeClass A has 30 students averaging 72 and class B has 20 averaging 82; find the combined mean.
ChallengeEight numbers average 12.5 and three of them average 10; find the mean of the other five.
ChallengeFive tests average 76 and the first three average 70; find the mean of the last two.
Error redoError clinic: five numbers average 20 and adding 32 raises the mean to 22; a student thought the total rose by only 2. By how much did the total rise?

03　Answers and one-line notes

#	Answer	One-line note
1	64 marks	The two totals are 300 and 276, and 576 divided by 9 gives 64.
2	86 marks	The weighted total 270 plus 160 is 430, and 430 divided by 5 gives 86.
3	360	24 times 15 gives 360.
4	17	The total falls from 216 to 204, and 204 divided by 12 gives 17.
5	35	The total 150 minus 115 leaves 35.
6	92 marks	The required total is 344 and 252 is already scored, so 92 more is needed.
7	76 marks	The totals are 2160 and 1640, and 3800 divided by 50 gives 76.
8	14	The total 100 minus 30 gives 70, and 70 divided by 5 gives 14.
9	85 marks	The total 380 minus 210 gives 170, and 170 divided by 2 gives 85.
10	32	The total rises from 100 to 132, an increase of 32, which is the number added.

04　What to do after marking

After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
Repeat the same item two days later; move to the next paper only when both attempts are correct.
Parents only need the answer and note columns; there is no need to explain every item.

Check the answers, and for any wrong item write down the total and the count first, then compute the mean again.Tutor Registration →

Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.