Q&A - PSLE Math

[alfretztay]

Hi

Need help on the below.

24 x 6/10 = 14.4 papaya (sold)
24 x 4/10 = 9.6 papaya (left)

6/10 and 3/4 , the common denominator is 20

6/10= 12/20(papaya sold)
3/4= 15/20(apple sold)

Hence, 8/20 (papaya) and 5/20 (apple) will be left.

Also, don't forget about the 9.6 papaya earlier.

[][][][][][][][][9.6]
[][][][][]<---30-->

3u -> 30-9.6= 20.4
1u -> 20.4/3= 6.8

6.8 x 12 + 14.4 x $2.30 = $220.80
$0.40 x 15 = 6

$220.80+$6=$226.80

Solved by DS.

Also, I would solve the above problem as follows :

100u + 24 - (100u + 24) x 0.6 - 25u ------- 30
1000u + 240 - 600u - 144 - 250u ------- 300
150u ------- 204
1u ------- 204/150 = 1.36
100u ------- 136
(136 + 24) x 0.6 x 2.30 = 220.80
136 x 0.75 x 0.40 = 40.80
40.80 + 220.80 = 261.60

Ans : $261.60.

[alfretztay]

In a factory , 585 of the workers are Chinese, 3/11 of the remainder are Malays and the rest are Indians. The Indians form 1/3 of the total number of workers. 1/2 of the Indians and 5/9 of the Malays are males.
(A) how many workers are there in the factory altogether?
(B) what is the ratio of the number of Indian male workers to the number of Malay male workers? Give your answer in its simplest form.


Please help. Thanks!!

Code: Select all

               Chinese(585) 
             /
Total Workers           Malay (3/11)
             \         /
              Others(?)
                       \
                        Indian (8/11)

8/11 X Others = 1/3
Others = 1/3 X 11/8 = 11/24

a) Therefore chinese make up of 24/24 -11/24 = 13/24

13/24 => 585
24/24 => 1080

b)Out of others,
Malays => 3/11 =>9/33
Males is 5/9 => 5/33

Indians=>8/11=>24/33
Males is 1/2=>12/33

Indian Male : Malay Male => 12:5

Alternatively,

(a)
C ------- 585
M ------- 3u
I -------- 11u - 3u = 8u
1/3 ------- 8u
2/3 ------- 8u x 2 = 16u = 585 + 3u
13u ------- 585
1u ------- 585/13 = 45
11u ------- 45 x 11 = 495
495 + 585 = 1080

(b)
8u ------- 45 x 8 = 360 (total Indians)
360/2 = 180 (male Indians)
3u ------- 45 x 3 = 135 (total Malays)
(5/9) x 135 = 75 (male Malays)
number of Indian male workers to the number of Malay male workers ------- 180 : 75 = 12 : 5.

Ans : (a) 1080 workers; (b) 12 : 5

[alfretztay]

1

300(t - 6) = 200(t + 3)
300t - 1800 = 200t + 600
100t = 2400
t = 24
d = 300(24 - 6) = 300 x 18 = 5400 or
200(24 + 3) = 200 x 27 = 5400
5400m = 5.4km

Ans : 5.4km or 5400m.

2

Forks ------- 1u x $4.10 = $4.1u
Spoons -------- (1u + 1u + 6) x $6.05 = $(12.1u + 36.3)
Knives ------- (1u - 6) x $3.60 = $(3.6u - 21.6)
(3.6u - 21.6) + (12.1u + 36.3) + 4.1u ------- 410.7
19.8u ------- 396
1u ------- 396/19.8 = 20
1u + 1u + 6 = 2 x 20 + 6 = 46

Ans : 46 spoons.

[NerdyMath]

Code: Select all

Test

[ozora]

Need some help on the following questions
1
2
3
Thanks

[alfretztay]

Need some help on the following questions
1

300(t - 6) = 200(t + 3)
300t - 1800 = 200t + 600
100t = 2400
t = 24
d = 300(24 - 6) = 300 x 18 = 5400 or
200(24 + 3) = 200 x 27 = 5400
5400m = 5.4km

Ans : 5.4km or 5400m.

2

Forks ------- 1u x $4.10 = $4.1u
Spoons -------- (1u + 1u + 6) x $6.05 = $(12.1u + 36.3)
Knives ------- (1u - 6) x $3.60 = $(3.6u - 21.6)
(3.6u - 21.6) + (12.1u + 36.3) + 4.1u ------- 410.7
19.8u ------- 396
1u ------- 396/19.8 = 20
1u + 1u + 6 = 2 x 20 + 6 = 46

Ans : 46 spoons.

Thanks

[ozora]

Need some help on the following questions
1

300(t - 6) = 200(t + 3)
300t - 1800 = 200t + 600
100t = 2400
t = 24
d = 300(24 - 6) = 300 x 18 = 5400 or
200(24 + 3) = 200 x 27 = 5400
5400m = 5.4km

Ans : 5.4km or 5400m.

2

Forks ------- 1u x $4.10 = $4.1u
Spoons -------- (1u + 1u + 6) x $6.05 = $(12.1u + 36.3)
Knives ------- (1u - 6) x $3.60 = $(3.6u - 21.6)
(3.6u - 21.6) + (12.1u + 36.3) + 4.1u ------- 410.7
19.8u ------- 396
1u ------- 396/19.8 = 20
1u + 1u + 6 = 2 x 20 + 6 = 46

Ans : 46 spoons.

Thanks

thanks

[Ender]

Need some help on the following questions
3
Thanks

Let u be the number of rows of 26 chairs per row.
26u + 50 =22(u+9)
26u= 22u + 148
u =37

In the end there are 37+9= 46 rows.

Brown , grey, grey, arrangement comes as a set of 3 rows, i.e each brown row appears once every 3rows.
Therefore number of brown rows =46÷3 =15, remainder 1 row.
Depending how you arrange them, bgg or gbg or ggb, you'll have either 15 rows or 16 rows of brown. Question asking for maximum number of browns, therefore it's 16 rows of brown that you want, the bgg format.

Max. number of brown chairs in the end is 16×22= 352 chairs.

[belnanna]

Please help to explain this question.. Thanks in advance.

[Ender]

Please help to explain this question.. Thanks in advance.

Distance =224 km
Time taken to complete the distance at slower pace= 56min
convert to hours = 56/60 = 14/15 hour

Slow speed = 224/(14/15) = 240 km/h

Usual speed= 240+40 = 280 km/h

Usual time wll be 224/280 = 0.8 hour or 0.8 X 60= 48 mins