Q&A - PSLE Math

[mrswongtuition]

I'm not sure if this is right, but based on my interpretation of the question:


Quantity of P:E is 1:7
P [__]
E [__][__][__][__][__][__][__]

Price of P & E (in total)
P [_______][_$9.10_] ````` } Total
E [_______] ````````````` }$100.10

By Price:
$100.10 - $9.10 = $91
2u -> $91
1u -> $45.50

Since there are 7 units of erasers, each unit of erasers will cost $45.50/7 = $6.50

The price of the pens is $45.50 + $9.10 = $54.60

Price of pens take away the price of 1 unit of erasers (to find the difference in amount if the same amount of pens & erasers were bought):
$54.50 - $6.50 = $48.10

Since each pen is more expensive than each eraser by $3.70,
$48.10/$3.70 = 13 pens

To find the price of each pen:
$54.60/13pens = $4.20

[Dharma]

Denise:

Jack bought some pens and erasers for a total of $100.10.

He spent $9.10 more on the pens than the erasers.
Each pen costs $3.70 more than each eraser.
Jack bought 6 times more ereasers than pens. How much does each pen cost?

Its correct

[Dharma]

mrswongtuition:

I'm not sure if this is right, but based on my interpretation of the question:

Sorry ...the answer is right

[fxchow]

Hi,


Can someone help to solve this problem. TIA

Allen, Raymond and Tom ran at a speed of 5km/h, 6km/h and 7km/h respectively.
They ran along the same route and started at 6.00 am, 6.30 am and 7.00 am respectively.
When Raymond passed Allen, he gave Allen a message to pass to Tom.
What time will Tom receive the message?

[Denise]

ack bought some pens and erasers for a total of $100.10.

He spent $9.10 more on the pens than the erasers.
Each pen costs $3.70 more than each eraser.
Jack bought 6 times more ereasers than pens. How much does each pen cost?
How many pens and how erasers did he buy then?

[Dharma]

fxchow:

Hi,


Can someone help to solve this problem. TIA

Allen, Raymond and Tom ran at a speed of 5km/h, 6km/h and 7km/h respectively.
They ran along the same route and started at 6.00 am, 6.30 am and 7.00 am respectively.
When Raymond passed Allen, he gave Allen a message to pass to Tom.
What time will Tom receive the message?

for

Hi,

At 7am, Allen already travelled (5x1)km. Need to calculate time for Tom catch up this dist.

Time for Tom to catch up = 5km/ (Speed of Tom - Speed of Allen)
= 5/(7-5) = 2.5hrs.

Tom will pass Allen at 9.30am ...is the time Allen passes the message to him

[Dharma]

Denise:

ack bought some pens and erasers for a total of $100.10.

He spent $9.10 more on the pens than the erasers.
Each pen costs $3.70 more than each eraser.
Jack bought 6 times more ereasers than pens. How much does each pen cost?
How many pens and how erasers did he buy then?

Hi,

Qty:
Pens : 1 unit
Erasers : 7 units

Cost:
Pens : 1 part +$3.70
Eraser : 1 part

Value :
Pens : (1 unit)x(1 part +$3.70)
Erasers : (7 units)x(1 part)

(8 units)(1 part) +(1unit)($3.70) = $100.10
(1 unit)($3.70) - (6 units)(1 part) = $9.10

(14 units)(1 part) = $ 91
(1 unit)(1 part) = $6.50
(8 units)(1 part) = $52

(1 unit)($3.70) = $100.10 - $52 = $48.10
1 unit = 13

No. of pens : 13
No. of erasers : 13 x 7 = 91

[Denise]

Ok. I get it. Thank you very much

[fxchow]

Dharma:

fxchow:

Hi,


Can someone help to solve this problem. TIA

Allen, Raymond and Tom ran at a speed of 5km/h, 6km/h and 7km/h respectively.
They ran along the same route and started at 6.00 am, 6.30 am and 7.00 am respectively.
When Raymond passed Allen, he gave Allen a message to pass to Tom.
What time will Tom receive the message?

for

Hi,

At 7am, Allen already travelled (5x1)km. Need to calculate time for Tom catch up this dist.

Time for Tom to catch up = 5km/ (Speed of Tom - Speed of Allen)
= 5/(7-5) = 2.5hrs.

Tom will pass Allen at 9.30am ...is the time Allen passes the message to him

Hi Dharma,

I got it. Thanks so much!

[tianzhu]

Other than Guess and Check, what are the other alternatives to solve this problem?


Annie wrote her mother’s age followed by her own age to form a 4-digit number.She used the difference between their ages to subtract from the 4-digit number. Then Annie obtained the number 4489.What was Annie’s age ? (RGPS P6 Prelim 2008 Q47)