Q&A - P4 Math

[shurley197323]

tianzhu:

shurley197323:

[Thank you & Sorry, Tianzhu,

I still can't get ( 1600 ) & (36) ?

Can help to show me step by step ?

Thks in advance.

Hi

From 1 to 79, there are 40 number of odd numbers.

sum of odd numbers from 1 to nth term ------ n*n (n square)

40*40 ----- 1600

36 is the sum of odd numbers from 1 to 11 (1+3+5+7+9+11)

Best wishes

OK. Thanks Tianzhu

[peapot]

Hi everyone! Pls help me with following q.


Mr Lee arranged some chairs in 15rows, such that there were equal number of chairs in each row. When he removed 5 rows of chairs and placed them on the remaining 10rows, the number of chairs in each row increased by 6. What was the number of chairs in each row at first?

[tianzhu]

peapot:

Hi everyone! Pls help me with following q.


Mr Lee arranged some chairs in 15rows, such that there were equal number of chairs in each row. When he removed 5 rows of chairs and placed them on the remaining 10rows, the number of chairs in each row increased by 6. What was the number of chairs in each row at first?

Hi

10*6 ----- 60

These 60 chairs were from the original 5 rows.

Number of chairs in each row at first ------ 60/ 5 ------ 12

Best wishes

[peapot]

Oh! Tianzhu Thks!! You make it looks so easy!!


I have one more q on perimeter, no dimensions given. Need to post pic.

[milo-cupcake]

Can anyone help with the following question?


http://i40.tinypic.com/333z4v4.jpg\">

Thanks in advance.

[The Right Equation]

milo-cupcake:

Can anyone help with the following question?


http://i40.tinypic.com/333z4v4.jpg\">

Thanks in advance.

concepts involved:
1) total quantity remains unchanged
2) work backwards

method 1:
http://i44.tinypic.com/35koqi8.jpg\">

method 2:
http://i39.tinypic.com/fn45q8.jpg\">

method 2 is for explanation purposes (since if it is a p4 qn, not allowed to use ratio)

[milo-cupcake]

The Right Equation:

milo-cupcake:

Can anyone help with the following question?


http://i40.tinypic.com/333z4v4.jpg\">

Thanks in advance.

concepts involved:
1) total quantity remains unchanged
2) work backwards

method 1:
http://i44.tinypic.com/35koqi8.jpg\">

method 2:
http://i39.tinypic.com/fn45q8.jpg\">

method 2 is for explanation purposes (since if it is a p4 qn, not allowed to use ratio)

:thankyou: The Right Equation

[peapot]

pls help me with this.

[peapot]

http://i39.tinypic.com/f0805.jpg\">

[Funz]

peapot:

http://i39.tinypic.com/f0805.jpg\">

is the ans 36cm & 16cm sq?