• RE: Hwa Chong Institution (High School)

    ljk:
    Hi HCI parents,

    What is the usual dismissal time in Sec 1? My son isn't taking any 3rd language. I saw the 2013 timetable and there was AEP/MSP/PRP/etc. from 2:20 - 4:50pm. What do those acronyms stand for? Thanks.
    AEP: Art Elective Program
    MSP: Malay Special Program
    PRP is some reading thing iirc

    Basically it's the special programs

  • RE: O-Level Additional Math

    mummytofour:
    0xBB40E64E:

    [quote=\"mummytofour\"]Hi, my daughter has some problems with her sec one maths questions so could anyone help her? thx!

    1)Given that 106480=2^4 × 5 × 11^3 , find the smallest value for x where 106480x is a perfect square and x is an integer.
    2)Find two numbers if their HCF (highest common factor) is 5 and their LCM (lowest common multiple) is 175.
    3)The lowest common multiple of 6,9, and x is 126. Find the two possible values of x which are odd numbers.
    4)The HCF (highest common factor) of two numbers is 1 and the LCM of these numbers is 51. What are the two numbers?
    5)The product of the ages of a group of people from 20 years to 25 years is 11088. Find
    (i) the number of people in the group,
    (ii) the sum of their ages.

    1)
    For a number to be a perfect square, the power of the prime factors must be a multiple of 2, aka 2^2 x 3^4 is fine, but 2^2 x 3^3 is not.

    So, for 106480, you make the powers all even,
    2^4 × 5 × 11^3 => 2^4 x 5^2 x 11^4
    what you added was 5 x 11 = 55.
    To check, 106480 x 55 = 5856400 which is a perfect square

    2)
    HCF = 5
    LCM = 5^2 x 7

    As the LCM is 5, both numbers must be multiples of 5

    No-1: 5
    No-2: 5

    As LCM has a 5^2, one of the numbers must have a multiple of 5^2. Both numbers cannot be multiples of 5^2 as if they are, the LCM would be 5^2 instead of 5.

    No-1: 5^2
    No-2: 5

    As LCM has a 7, one of the numbers must be a multiple of 7. As explained above, both numbers cannot be multiples of 7.

    No-1: 5^2 = 25
    No-2: 5 x 7 = 35

    25, 35

    3)
    No-1 : 2 x 3
    No-2 : 3^3
    No-X : ?
    LCM : 2 x 3^2 x 7

    As none of the numbers there are multiple of 7, but the LCM is a multiple of 7, x must be a multiple of 7.

    1st ans : 7

    As x must be multiple of 7, the other number must be 3 x 7, as we can't use 2 x 7 (must be odd)

    2nd ans : 21

    7 , 21

    4)
    3,17

    5i) 3

    5ii)67


    Sorry, I'll add the explanations soon. These questions are actually quite interesting! Never seen some of them before and also quite challanging 😄

    Hi 0xBB40E64E, thank you so much for your answers and explanation!
    :thankyou:
    My daughter understood it after seeing your solution 😂 By the way, the questions are from a sec one math assessment book...and there are answers at the back and all of your answers are right, except for question 3 . Its supposed to be 21 and 63, but you got 21 right! :rahrah: Anyway thanks so much because i didnt know how to explain it to her
    :thankyou:[/quote]
    You're welcome 😃
    It's good to know my answers are correct, builds self-confidence haha

    Also, 63 is acceptable, but 7 is also right!
    http://i.imgur.com/xDU7iiI.png\">
    There can actually be multiple answers for this question =P

  • RE: O-Level Additional Math

    mummytofour:
    Hi, my daughter has some problems with her sec one maths questions so could anyone help her? thx!

    1)Given that 106480=2^4 × 5 × 11^3 , find the smallest value for x where 106480x is a perfect square and x is an integer.
    2)Find two numbers if their HCF (highest common factor) is 5 and their LCM (lowest common multiple) is 175.
    3)The lowest common multiple of 6,9, and x is 126. Find the two possible values of x which are odd numbers.
    4)The HCF (highest common factor) of two numbers is 1 and the LCM of these numbers is 51. What are the two numbers?
    5)The product of the ages of a group of people from 20 years to 25 years is 11088. Find
    (i) the number of people in the group,
    (ii) the sum of their ages.
    1)
    For a number to be a perfect square, the power of the prime factors must be a multiple of 2, aka 2^2 x 3^4 is fine, but 2^2 x 3^3 is not.

    So, for 106480, you make the powers all even,
    2^4 × 5 × 11^3 => 2^4 x 5^2 x 11^4
    what you added was 5 x 11 = 55.
    To check, 106480 x 55 = 5856400 which is a perfect square

    2)
    HCF = 5
    LCM = 5^2 x 7

    As the LCM is 5, both numbers must be multiples of 5

    No-1: 5
    No-2: 5

    As LCM has a 5^2, one of the numbers must have a multiple of 5^2. Both numbers cannot be multiples of 5^2 as if they are, the LCM would be 5^2 instead of 5.

    No-1: 5^2
    No-2: 5

    As LCM has a 7, one of the numbers must be a multiple of 7. As explained above, both numbers cannot be multiples of 7.

    No-1: 5^2 = 25
    No-2: 5 x 7 = 35

    25, 35

    3)
    No-1 : 2 x 3
    No-2 : 3^3
    No-X : ?
    LCM : 2 x 3^2 x 7

    As none of the numbers there are multiple of 7, but the LCM is a multiple of 7, x must be a multiple of 7.

    1st ans : 7

    As x must be multiple of 7, the other number must be 3 x 7, as we can't use 2 x 7 (must be odd)

    2nd ans : 21

    7 , 21

    4)
    LCM : 3 x 17

    HCF = 1 means that the two numbers do not share any common factors (other then 1)

    Ans must be 3 and 17 then.

    3,17

    5i)
    11088 = 2^4 x 3^2 x 7 x 11

    As the age of the people MUST be between 20-25

    The age of the first person must be 11 x 2 = 22 as 11 is less then 20, but multiplying 11 by any other number then 2 will lead to it being over 25.

    1st person: 22

    Remaining ages : 2^3 x 3^2 x 7

    Age of the second person has to be 7 x 3 as 7 x 2 is less then 20 and
    7 x 2^2 or 7^3 are over 25.

    2nd person : 21

    Remaining ages : 2^3 x 3

    2^3 x 3 is the last person age. Amy other combination will lead to a number below 20.

    3rd person: 24

    Ans: 3 people

    5ii)
    22+21+24=
    67

    I'll admit these are pretty interesting and challenging questions. Had much fun working on them 😃

  • RE: Hwa Chong Institution (High School)

    wonderm:
    ljk:

    Thanks wonderm and 0xBB40E64 for your clarification.

    Just to clarify, would the marks from physics, chemistry and biology be divided equally to get an average and the average score is then added to calculate the msg?

    For Sec 1 and Sec 2, Science is considered as one subject. Each term there will only be one science test. Physics, chemistry and biology are taught during science lessons. For my two boys, the ways school covered the 3 sciences were not the same. So they may twist it again next year. Don't worry about the details for now.

    To further elaborate, there will only be one exam paper (LSS), and as for the mark allocation for the 3 modules, IIRC it's split evenly, but even if it's not, it's beyond anyone's control, so no point worrying about that.

    If you are really worried, you can from time to time ask to view their ePortfolio.

  • RE: Hwa Chong Institution (High School)

    ljk:
    When is Sec 1 registration at HCI? Is it 23 Dec?

    To maintain in IP, one has to get MSG < 3? Or is it 3 and below? How is msg score calculated? So worrying...have to closely monitor my child's progress to ensure he stays in the IP program. Stress!
    MSG= Mean Subject Grade aka Average grade of all subjects

    Eg:
    EL:A2
    Math:A1
    CL:B3
    Chem:A1
    Physics: B3
    History: B4

    MSG= (Sum of all subject grade) / (Number Of Subjects)
    = (2+1+3+1+3+4) / (6)
    = (14) / 6
    = 2.33

    A MSG below 3 aka Ave grade less then a B3 should be fine.