belnanna:

Hi, can some kind soul please help without solving this in algebra?

Thanks ....

Tom's present age is twice more than Sam's age years ago. Today, Sam's age is Tom's age the same number of years ago. How old is Tom now if the sum of their present age is 30?

Hi, it can be solved using model.

A common mistake by my student is \"twice more than\", they often mistake it as \"twice as much as\". In this question, \"Tom's present age is twice more than Sam's age years ago\", means Tom's present age is 3u, Sam's age years ago is 1u.

http://i57.tinypic.com/2qx822p.jpg\">

Hope this helps.

Cheers.

skvn:

A, B and C shared 360 cards. If A gives 10% of her cards to B and in turn B gives 2/7 of his cards to C, the ratio of A's cards to B's cards to C's cards will be 1:3:4. How many cards did B have at first ?

Hi, skvn

Ratio in the end -> A : B : C = 1 : 3 : 4
Total 8u -> 360
1u -> 45
in the end, A -> 45, B -> 135, C -> 180
B gave 2/7 to C, so left 5units
5u -> 135
1u -> 27
After A gave 10% to B, B has 7u -> 7x27 = 189

For A, left 90%, 90% -> 45, 10% -> 5 (A gave 5 cards to B)

No. of cards B had at first: 189 - 5 = 184

(at first, A had 50, B had 184, C had 126)


Hope this helps.

Cheers.

SAHM_TAN:

Hi quekcc,


I was stumped with what to do with 5 and 3.

Ask you a qn that sounds very silly.

At first when she had some apples, 5 and 3 were part of it. When she bought 48 apples, is there a need a include 5 and 3 in each unit too when it was 3 times what she originally bought? Meaning for each of the 3 units, each will have 5 and 3 like what you drew for what she had at first?

Thank you

quekcc:

http://i62.tinypic.com/11qira1.jpg\">

So, 2u = 48-5-3=40.

1u = 20.

Ans: At first, she had 20 apples.
[quote=\"fohope\"]Hi,
Please help me on this problem sum? Thank you in advance.

Sandy had some apples at first. After she gave 5 apples to her brother and ate 3 apples, she went to buy 48 apples. In the end, she had thrice as many apples as before. How many apples did she have first?


Hi,

Could a kind soul help me on how to draw the model for this?

Sincere thanks for your help.

[/quote]
Hi SAHM_TAN,

http://i60.tinypic.com/2w250yu.jpg\">

I think it is good to draw the 5 and 3 in the model for understanding especially for P3 kids. It is useful for cultivating a good habit in transferring the info of the questions into model at P3. Once they are used to it or going to upper level, then they can do without certain details.

Cheers.

Daddy:

PLease help. Thanks.


http://i57.tinypic.com/2m4ogmv.jpg\">

It can be solved using 'set'

1 set --> 8 bags of sweets and 1 bag of chocolate
Money collected for 1 set --> 8 x 5.5 + 2 = 46
No. of sets = 3128 / 46 = 68

No. of sweets sold --> 68 x 8 x 4 = 2176
No. of chocolates sold --> 68 x 8 = 544

Hope this helps.

Cheers

Daddy:

HI,


Have another hard question to ask. Thanks.

Alex, Ben and Caleb had some stamps. Alex had 90 stamps more than Ben, and Ben had 10 stamps more than Caleb. After Alex had given Ben 95 of his stamps and Caleb bought some stamps, Alex and Caleb had the same number of stamps while Ben had thrice as much as either of them.

a) How many stamps did Caleb have at first?
b) How many stamps did they have altogether at first?
:?

http://i61.tinypic.com/14rx20.jpg\">

Hope this helps.

Cheers

belnanna:

please help...its urgent.. Thanks very much


The cost of a birthday present was shared between benjamin and christopher. at first,benjamin paid 2/3 of what christopher paid. when benjamin paid $50 more, he ended up paying 4/5 of what christopher paid. how much was the cost of the present?

Hi use total unchanged (cost of the present is constant)
First B:C = 2:3 (total 5u)
After B:C = 4:5 (total 9u)

Change total units to 45u
First B:C = 2:3 (x9) --> 18:27
After B:C = 4:5 (x5) --> 20:25

2u --> 50
1u --> 25
Cost of present 45u --> $1125

Hope this helps.

Cheers,
Homeworkgurusg

belnanna:

homeworkgurusg:

[quote=\"belnanna\"]Need help, thanks..


The long staircase at a tourist attraction has 300 steps. Gerald climbed up the staircase 2 steps at a time while his father climbed up the staircase 3 steps at a time. How many steps on the long staircase were not stepped on at all by either Gerald or his father?

No. of steps by Gerald --> 150
No. of steps by his father --> 100
No. of steps by both of them --> 300/6=50
No. of steps being stepped --> 150+100-50=200
No. of steps not being stepped --> 300-200=100

Hope this helps.

Cheers,
Homeworkgurusg

No. of steps by both of them --> 300/6=50 = every 6 steps,they stepped together - but still dont understand why both stepped together will increase the unstepped amount.. please teach...[/quote]Hi, when we calculate the steps being stepped using 150+100, it added the 50 steps twice (stepped by both father and son). Therefore we need to minus 50 to get the correct stepped amount.

Hope this clarifies.

belnanna:

Please advise if answer is 80 or 800..

thanks

In a bookshelf,4/5 of the books are fiction books.1/3 of the remainder are non fiction books.the remaining books are magazines. there are 800 more fiction books than magazines. find the number of magazines in the bookshelf?

Fiction : non fiction : magazine = 12 : 1 : 2
10u --> 800
1u --> 80
2u --> 160 (magazine)

Hope this helps.

Cheers,
Homeworkgurusg

belnanna:

Need help, thanks..


The long staircase at a tourist attraction has 300 steps. Gerald climbed up the staircase 2 steps at a time while his father climbed up the staircase 3 steps at a time. How many steps on the long staircase were not stepped on at all by either Gerald or his father?

No. of steps by Gerald --> 150
No. of steps by his father --> 100
No. of steps by both of them --> 300/6=50
No. of steps being stepped --> 150+100-50=200
No. of steps not being stepped --> 300-200=100

Hope this helps.

Cheers,
Homeworkgurusg

fire_fly:

Cd you plus help....

From Red swastika sa12013:
The ratio of the age of Mdm Huda to her son's age is 5:1 now. In 7 years time, she would be thrice as old as her son. What is the total age of Mdm Huda and her son now?
Thank you. ...

Before ratio --> H : S = 5 : 1 (difference 4u)
After ratio --> H : S = 3 : 1 (difference 2u)
Age difference between Mdm Huda and her son is unchanged after 7 years

So make the difference same
After ratio (x2) --> H : S = 6 : 2 (difference 4u now, same as before)
1u (6u-5u) --> 7 years
Age of Mdm Huda now is 5u --> 5x7=35
Age of her son now is 1u --> 7

Hope this helps.

Cheers