Need Help on Primary 6 maths question.
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Hi All,
Need help to explain this maths question to my daughter. Pls help.
1) Mr Loo had to deliver 800 hampers in May. He received $4 for every hamper that was delivered successfully and $7 would be deducted from his salary for every hamper that was damaged. If his salary in May was $2,430 , how many hampers did Mr Loo deliver successfully?
Thanks.
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If he deliver 800 successfully = $3200
For every one damaged he earns $4 + $7 = $11 less
($3200 - $2430) / 11 = 77
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Pri school math is moving away from logical deduction to mastery of tricky words.
Where, in this Godless Sg, is the fairness to these young, impressionable, innocent, silent angels? -
This question is a variation of the "Up and Down or Right and Wrong" Type of Question in the PSLE Maths Exam.
Similar questions will be
1. An ant is climbing up a wall. How long will it take the ant to reach a 3m wall if the ant climbs up 3 cm and falls back 1 cm every second.
2. In a multiple choice question test, there are 4 choices for each question and there are 50 questions. If a student scores 2 marks for a correct answer and 1 mark will be deducted for a wrong answer. How many questions do the student answer correctly if this student scores a total of 67 marks ?
School teachers have already trained the PSLE students on these type of quesions. So, the question " Mr Loo had to deliver 800 hampers in May. He received $4 for every hamper that was delivered successfully and $7 would be deducted from his salary for every hamper that was damaged. If his salary in May was $2,430 , how many hampers did Mr Loo deliver successfully? " is not unfamiliar to the PSLE students. Indeed, an average PSLE student can solve the question easily.
PS : To some, it might be a surprise to them that the famous question " There are 100 cats and hens and there are 344 legs altogether. How many cats are there ?" is a variation of this type of question and the question is solved easily too by using the method used for this type of question.
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Originally posted by Lee012lee:
This question is a variation of the "Up and Down or Right and Wrong" Type of Question in the PSLE Maths Exam.
Similar questions will be
1. An ant is climbing up a wall. How long will it take the ant to reach a 3m wall if the ant climbs up 3 cm and falls back 1 cm every second.
2. In a multiple choice question test, there are 4 choices for each question and there are 50 questions. If a student scores 2 marks for a correct answer and 1 mark will be deducted for a wrong answer. How many questions do the student answer correctly if this student scores a total of 67 marks ?
School teachers have already trained the PSLE students on these type of quesions. So, the question " Mr Loo had to deliver 800 hampers in May. He received $4 for every hamper that was delivered successfully and $7 would be deducted from his salary for every hamper that was damaged. If his salary in May was $2,430 , how many hampers did Mr Loo deliver successfully? " is not unfamiliar to the PSLE students. Indeed, an average PSLE student can solve the question easily.
PS : To some, it might be a surprise to them that the famous question " There are 100 cats and hens and there are 344 legs altogether. How many cats are there ?" is a variation of this type of question and the question is solved easily too by using the method used for this type of question.
1. So if the ant climbs 3 cm and falls 1 cm every second, it means that the ant climbs 2 cm every second. So 3 m / 2 cm -> 150 seconds.
2. Student gets 2 marks for correct answer and loses 1 mark for wrong answer, so it means that the student actually loses 3 marks per wrong question, considering the total to be 100 marks for 50 questions.
Then 100 - 67 = 33. So the students got 11 questions wrong. 39 * 2 = 78, 78 - 11 = 67 marks.
Haha, this is fun.
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Originally posted by d3sT1nY:
1. So if the ant climbs 3 cm and falls 1 cm every second, it means that the ant climbs 2 cm every second. So 3 m / 2 cm -> 150 seconds.
2. Student gets 2 marks for correct answer and loses 1 mark for wrong answer, so it means that the student actually loses 3 marks per wrong question, considering the total to be 100 marks for 50 questions.
Then 100 - 67 = 33. So the students got 11 questions wrong. 39 * 2 = 78, 78 - 11 = 67 marks.
Haha, this is fun.
Glad to hear that you find that it is fun to solve the questions.
Indeed, similar method is used to solve the famous question
There are 100 cats and hens and there are 344 legs altogether. How many cats are there ?
As usual, assume that all animals are cats ie there will be 100 x 4 legs = 400 legs
Now, for every 2 legs less means 1 hen.
400 - 344 = 56 legs less
So, 56/2 = 28 hens
Hence, there are 100 - 28 = 72 cats
Check : 72 x 4 + 28 x 2 = 344 legs.