Q&A - PSLE Math

[SOS mum]

Hi, ps help..tks and God Bless:)

Lynnette bought 6 brushes and 2 boxes of poster colors. She gave $103.40 to the cashier and received a change of $25. Given that 8 brushes and a box of poster colors cost the same as 3 brushes and 2 boxes of poster colours, what is the cost of 5 boxes of poster colours.

[PiggyLalala]

Hi, ps help..tks and God Bless:)

Lynnette bought 6 brushes and 2 boxes of poster colors. She gave $103.40 to the cashier and received a change of $25. Given that 8 brushes and a box of poster colors cost the same as 3 brushes and 2 boxes of poster colours, what is the cost of 5 boxes of poster colours.

8 brushes and one poster color cost the same as 3 brushes and 2 boxes of poster colours....
means cost of 5 brushes = cost of one poster colour.

6 brushes + 2 boxes of poster colours = 103.40 -25= 78.40
6 brushes +2x5 brushes = 78.40
16 brushes = 78.40/16 =4.90
5 boxes of poster colours = 4.9×5×5= 122.50

[SOS mum]

Sorry, ps help the following too. Many tks and God Bless:)

(1) Welsona has some money. She spent $17.40 on 3 notebooks and 8 highlighters. He is short of 80cents if he were to buy another notebook. However, if he were to buy another highlighter, he will have 60cents left.

(a) Find the cost of a notebook.
(b) How much money does Welson have?

(2) Xania and Criven cycle from Town A to Town B which is 87.5km apart. Xania cycles at a speed of 27 km/h and Criven cycles at a speed of 35 km/h.

(a) If Xania starts cycling 40 minutes earlier than Criven, how long will Criven take to catch up with her.
(b) How far away is Xania from Town B when Criven arrives at Town B

(3) During an interclass game, each group of pupils had to collect as many colored balls as possible from a box. Each colour represents a certain number of points as shown below.

Yellow 4
green 3
red 5

The number of yellow balls in the box was 20% more than the number of red balls and 10% less than the number of green balls. If a group of pupils managed to collect all the balls and the total possible points was 1035, how many yellow and red balls were there in the box altogether.

[nicnac]

Sorry, ps help the following too. Many tks and God Bless:)

(1) Welsona has some money. She spent $17.40 on 3 notebooks and 8 highlighters. He is short of 80cents if he were to buy another notebook. However, if he were to buy another highlighter, he will have 60cents left.

(a) Find the cost of a notebook.
(b) How much money does Welson have?

(2) Xania and Criven cycle from Town A to Town B which is 87.5km apart. Xania cycles at a speed of 27 km/h and Criven cycles at a speed of 35 km/h.

(a) If Xania starts cycling 40 minutes earlier than Criven, how long will Criven take to catch up with her.
(b) How far away is Xania from Town B when Criven arrives at Town B

(3) During an interclass game, each group of pupils had to collect as many colored balls as possible from a box. Each colour represents a certain number of points as shown below.

Yellow 4
green 3
red 5

The number of yellow balls in the box was 20% more than the number of red balls and 10% less than the number of green balls. If a group of pupils managed to collect all the balls and the total possible points was 1035, how many yellow and red balls were there in the box altogether.

(1) each notebook costs $1.40 more than a highlighter.
11u--> 13.20
1u--> !.20
Notebook--> 1.20+1.40=2.60

Amount he has --> 17.40 + (2.60- 0.8) = $19.20


(3) R : Y : G
100 120

90 100

30 : 36 : 40

30u(5) + 36u(4) + 40u(3) = 1035
U=2.5
Y+ R --> 66u --> 165

[Ender]

Sorry, ps help the following too. Many tks and God Bless:)

(2) Xania and Criven cycle from Town A to Town B which is 87.5km apart. Xania cycles at a speed of 27 km/h and Criven cycles at a speed of 35 km/h.

(a) If Xania starts cycling 40 minutes earlier than Criven, how long will Criven take to catch up with her.
(b) How far away is Xania from Town B when Criven arrives at Town B

2a) Xania had a head start of 40/60 X 27 = 18km
Criven is 8 km/h faster than Xania.
To close the gap of 18km at 8km/h,
Time take for Criven to catch up will be 18/8 = 2.25hrs
or 2 hours and 15 mins #

b)
Time taken for Criven to reach town B = 87.5/35 = 2.5hrs
In that same time, Xania's distance will be (27 X 2.5 ) + 18 = 85.5km
Therefore Xania's distance from town B = 87.5 - 85.5 = 2km#

[ozora]

Need some guide on the following question.
In June , 940 more boys than girls went to the library.
In July, the number of girls increased by 35% while the boys decreased by 15%.
If 1943 children visited in July, how many boys visited the library?

thanks

In June, G ->u, B-> u+940
In July, G -> 1.35u, B->0.85(u+940)

1.35u + 0.85u + 799 -> 1943
2.2u -> 1144
u -> 520

Boys visited library in July -> (520+940)0.85 = 1241

Thanks. Appreciate

[ozora]

May I know is there any other alternative method to find 2 to power of 20 besides using calculator?
Any short cut method or formula?

[Nickal]

Hi! need some help here. Thanks!
What is the digit in the ones place in the product of the following
9x99x999x9999x99999x999999x9999999
x99999999x999999999

[alfretztay]

Hi! need some help here. Thanks!
What is the digit in the ones place in the product of the following
9x99x999x9999x99999x999999x9999999
x99999999x999999999

The digits in the ones place are as follows :

9 -------> 9

9 x 9 -------> 1

9 x 9 x 9 -------> 9

9 x 9 x 9 x 9 -------> 1

...

9 x 9 x 9 x 9 x 9 x 9 x 9 x 9 x 9 -------> 9


Ans : 9.

[Jmaths.SG]

May I know is there any other alternative method to find 2 to power of 20 besides using calculator?
Any short cut method or formula?

Don't really have any smart ideas, but you can try...

2^20
= 4^10
= 16^5
= 16*16*16*16*16