Foong Jia Heng
Asked 9 years ago

SG chevron_right chevron_right

How do I do this question

Replies 4
Shaoyang Brandon

Prime factors are numbers that can only be divided by 1 and itself. So, 30 = 1 x 30 = 2 x 15 = 3 x 10 = 5 x 6 So, the prime factors are 2, 3 and 5. Their sum is 2 + 3 + 5 = 10 :)

6 years ago
Soo Vei Li

This question may be asking for the sum of all prime NUMBERS (not FACTORS) less than 30. Otherwise it would have been simply 'sum of all prime factors of 30', without having to specify 'less than'. If the former, then need to add the 10 prime numbers 2, 3, 5, ... 29 and add them up.

6 years ago
Ariel Lim Ah Ping

Sec 1 liao. Lai lai. Join us here https://mobile.facebook.com/groups/896114413789189?ref=bookmarks

6 years ago
Tamil Selvan

2,3,5,7,11,13,17,19,23,29. Prime numbers.

6 years ago

Cheryl Lee
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

Pls help. P5 Question. Thank u.

Replies 3
Tamil Selvan

9865423 greatest. Odd number 2345698 smallest. Even number

6 years ago
Cheryl Lee

Thank You

6 years ago
Soo Vei Li

The question requires students to apply their understanding of how numbers may be compared. That is, in a string of digits, we look from the left to the right. So to form the largest number, we need to place the largest number on the left, then second largest, etc. Finally, to form an odd number, we need to place the 3 at the end. Same idea for the smallest even number.

6 years ago
Cheryl Lee

Thank You

6 years ago

Kai Xin
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

P5 Question. Pls Help.

Replies 3
Lee AG

6 years ago
Kai Xin

Thanks for ur help. 😊

6 years ago
Lee AG

No problem.

6 years ago
Kai Xin

Thanks for ur help. 😊

6 years ago
Lee AG

No problem.

6 years ago

Magdalene Sim
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Number and Algebra

pri 6 qns, please assit. thanks

Replies 1
Lee AG

6 years ago

Theresa Leong
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

Hi all, can someone pls advise? P5 question.

Replies 6
Kai Meng

Hi, divisible by 5 and 3 means divisible by 15. Even number x 15 must end with 0. 120 is one such number.

6 years ago
Theresa Leong

Oh I see. Thank you so much for your help. I appreciate it.☺

6 years ago
Kai Meng

Welcome. Of course, even number x 5 is enough to determine the last digit being 0.

6 years ago
Theresa Leong

Thank you.👍

6 years ago
Shaoyang Brandon

Hi! For (a), the digit is 0 because multiples of 5 have either 5 or 0 in the ones place. 5 is not possible because it would give an odd digit in the ones place. So, 0 is the digit. For part (b), since this three digit number is a multiple of 3 and has a 0 in the ones place, therefore, the tens and hundreds together must be multiples of 3. For example, 120, 150, 180, 210, 240, ...930, 960, 990. :)

6 years ago
Theresa Leong

Thank you so much for the detailed explanation. You guys are awesome.😊

6 years ago
Theresa Leong

Oh I see. Thank you so much for your help. I appreciate it.☺

6 years ago
Kai Meng

Welcome. Of course, even number x 5 is enough to determine the last digit being 0.

6 years ago
Theresa Leong

Thank you.👍

6 years ago
Theresa Leong

Thank you so much for the detailed explanation. You guys are awesome.😊

6 years ago

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