Lower Secondary Mathematics

[ChewingPencilLine]

Question 3


Let x be the time at which Steven met Jason in minutes, after the 3 of them started walking from Town A to B or B to A respectively.

in x minutes, Steven would have walked 100x meters.
in x minutes, Jason would have walked 80x meters.

Since Steven and Jason must have met some point in between town A and town B, we know that the distance between Town A and Town B is given by
100x + 80x = 180x ----------- (1)

in x + 6 minutes, Steven would have walked 100 (x+6) = 100x + 600 meters.
in x + 6 minutes, Melvin would have walked 75 (x+6) = 75x + 450 meters.

Since Steven and Melvin must have met some point in between town A and town B, we know that the distance between Town A and Town B is given by
100x + 600 + 75x + 450 = 175x + 1050 ----------- (2)

Equating the 2 equations, you get
180x = 175x + 1050
5x = 1050
x = 210

Recall that the total distance between town A and town B is given by 180x (equation 1).
Therefore, 180 * 210 = 37800 meters = 37.8 km

[ChewingPencilLine]

The key is to read the question and understand what x should be used to stand for. A lot of the times, x is used to stand for the quantity you are looking for. For example, look at question 2. I used x to stand for the amount of cashew nuts to be mixed in, in pounds.


However, this is not always the case. Try to think and see what quantity x should represent to simplify the question. For example, in question 3, it is obvious that the common quantity between scenario 1 (Steven meeting Jason) and scenario 2 (Steven meeting Melvin) is the time at which Steven passed Jason (they tell you that Steven met Melvin 6 mins after passing Jason!).

Hope I have helped some!

[PuffyCakes]

Thx alot kind souls<3

[ChewingPencilLine]

Haha, no problem. And it is just one soul Me!

[PuffyCakes]

U helped me alot:)

[mathtuition88]

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[Augs]

Hi. Does anyone know of any good Sec 1NA Maths assessment book? I prefer it to go topic by topic, instead of in exam papers format. I went to Lot One popular and could only find 2 types of Maths assessment books for Sec 1 NA, and both are in exam papers format. Any recommendation on which assessment books and which outlet to get?

[Augs]

Hi. Does anyone know of any good Sec 1NA Maths assessment book? I prefer it to go topic by topic, instead of in exam papers format. I went to Lot One popular and could only find 2 types of Maths assessment books for Sec 1 NA, and both are in exam papers format. Any recommendation on which assessment books and which outlet to get?

[mummy so kiasu]

Augs:

Hi. Does anyone know of any good Sec 1NA Maths assessment book? I prefer it to go topic by topic, instead of in exam papers format. I went to Lot One popular and could only find 2 types of Maths assessment books for Sec 1 NA, and both are in exam papers format. Any recommendation on which assessment books and which outlet to get?

Have you try asking the popular staff to recommend?

[SZ Venture]

you can try the casco mathematics tutor, though is for express students. but the difference between express & NA is just that NA takes a longer time to finish the topics.

ultimately, they take the same O level paper.