Foong Ling
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Number and Algebra

Cam help! Thanks.

Replies 4
Chia-Chan Bk

6 years ago
Xavier Sng

6 years ago
Foong Ling

Chia-Chan Bk why is 150km =3h

6 years ago
Chia-Chan Bk

Total distance = 60×5=300 km 3pm car travelled 60x3=180 km 180-30 = 150 km for van to complete the journey. Van had completed 300 -150 =150 km fr noon to 3pm (3h). Van needs another 3 h to complete the other 150 km.

6 years ago

Ging Yang Choo
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Number and Algebra

P4 question. Please assist. TIA.

Replies 1
Yeo See Yeong

6 years ago

Fiona Fong
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Number and Algebra

Please help

Replies 2
Chia-Chan Bk

6 years ago
Fiona Fong

Thks.

6 years ago

Aly Koh Kai Lin
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

Need help on both qn . Thanks!

Replies 0

Ging Yang Choo
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Number and Algebra

I'm sure there's a faster method than "guess n check". Someone please advise. TIA.

Replies 4
Jatuporn Chinrungrueng

Let x and y be peanuts and cookies bought respectively in units of 100 g. Then we can write an equation 0.85 x + 0.40 y = 12, or 85x + 40y = 1200 --------- (1) rearrange eq (1) and divide by 40 we get 85x/40 = 30 - y ------------- (2) Consider eq (2), we have multiple solutions, but if we limit x and y to only whole number (in units of 100 g- in other words, Lynette could not buy 20 g or 120 g for example) Then what we are left is to figure out an X such that 85x/40 gives out an integer. And the answers are x is either 0 or 8, meaning Lynette either bought 0 g. of peanuts and 3000 g. of cookies OR 800 g. of peanuts and 1300 g. of cookies. I don't think you can find solution without checking in this case.

6 years ago
Ging Yang Choo

Jatuporn Chinrungrueng, tks for your reply.

6 years ago
Chia-Chan Bk

6 years ago
Ging Yang Choo

Chia-Chan Bk, many thanks.

6 years ago

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