Q&A - PSLE Math

[belnanna]

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

Thank you Ender! You're such a nice person,always helping us out so quickly. So much of your painstaking efforts.. Appreciated deeply!

[Ender]

Thank you Ender! You're such a nice person,always helping us out so quickly. So much of your painstaking efforts.. Appreciated deeply!

Pleasure is mine, becoz I'm am coaching my son in the PSLE too. The questions you guys/gals posted, are helpful to him too for practice.

[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

It is my pleasure.

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

[ozora]

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.

Thanks for the note . Thus the reminder is inclusive .

[ozora]

Need guide on these last two questions.

[Ender]

Let" u" be the number of parts for the banner,
and "p" be the number of parts for the flags.

Expressed the length of the strings
0.8u =1.2p
p=8/12*u=2/3*u

Banners=2u,
Flags = 5p,
5p-2u = 44
10/3*u-2u=44
10/3*u-6/3*u =44
4/3*u = 44
u = 33

Banner =2u=2X33=66

[ozora]

Let" u" be the number of parts for the banner,
and "p" be the number of parts for the flags.

Expressed the length of the strings
0.8u =1.2p
p=8/12*u=2/3*u

Banners=2u,
Flags = 5p,
5p-2u = 44
10/3*u-2u=44
10/3*u-6/3*u =44
4/3*u = 44
u = 33

Banner =2u=2X33=66

thanks again Ender

[alfretztay]

Need guide on these last two questions.

Alternatively,

80cm ------- 2 banners
1.2m = 120cm ------- 5 flags
LCM of 80 and 120 is 2 x 2 x 2 x 2 x 3 x 5 = 240
240cm ------- 2 x 3 = 6 banners
240cm ------- 5 x 2 = 10 flags
10 - 6 = 4
44/4 = 11
11 x 6 = 66

Ans : 66 banners.

[voltes5]

Need help please...could not understand the answer sheet.

Patricia baked 120 more cupcakes than muffins. She sold 5/6 of the cupcakes and 1/5 of muffins. In the end she had 75 more muffins than cupcakes left. How many cupcakes and muffins did she bake at first?

[voltes5]

Thanks in advance for the help.

Sally bought some chocolates and gave half of them to Mabel. Sally also bought some lollipops and gave half of them to Mabel. Mabel ate 7 lollipops and Sally ate 16 chocolates.

After that, the number of lollipops and chocolates Mabel had were in the ratio 1:8 and the number of lollipops and chocolates Sally had were in the ratio 1:5. How many lollipops did Sally buy at first?

Answer says 48 but I could not understand how to arrive at it.