Tutor MathsGuru: Ask me for your burning Maths questions!

[Tang]

Almighty:

tutortamil:

[quote=\"ksi\"]
+10, -5, +15, -5, +20, -5, +25

So the next number is 80.

Thanku very much Ksi. I was struggling with it yesterday fully.

[/quote]Hello,

25 to 30 is +5 and not -5.

You may want to check again.

[corneyAmber]

Almighty:

Complete the pattern:


5, 15, 10, 25, 30, 50, 55, ?

+10, -5, +15, +5, +20, +5, +25

[/quote]

+10, -5, +15, +5, +20, +5, +25, -5, +30, +5, +35, +5.....

Almighty, is 80 correct? If it is then there are 2 alternating series in this and even my initial error has no impact. Otherwise gotta rework.

[Almighty]

s 80 was the answer

[Almighty]

CAN ANYONE HELP ON THESE TWO PROBLEMS:

1) Mei and Lin took part in a cycling race. Mei cycled at a speed of 20 Km/h. Bothof them did not change their speed throughout the race.When Lin civered 1/2 the distance, Mei was 3.5 km in front of her.Mei reached the finishing line at 10.45am.What time did Lin reach the finishing line?

2) David and Michael drove from Town A to Town B at different speeds. Both didnot change their speeds throughout their journeys.
David started his journey 30 minutes earlier than Michael. When Michael reached Town B 50 minutes earlier than David, David had travelled 4/5 of the journey and was 75 Km away from Town B.a) What was the distance between Town A and Town B?
b) How many Kilometres did David travel in 1 hour?
c) What was the time taken by Michael to travel from Town A to Town B?

[Dharma]

Almighty:

CAN ANYONE HELP ON THESE TWO PROBLEMS:

1) Mei and Lin took part in a cycling race. Mei cycled at a speed of 20 Km/h. Bothof them did not change their speed throughout the race.When Lin civered 1/2 the distance, Mei was 3.5 km in front of her.Mei reached the finishing line at 10.45am.What time did Lin reach the finishing line?

2) David and Michael drove from Town A to Town B at different speeds. Both didnot change their speeds throughout their journeys.
David started his journey 30 minutes earlier than David. When Michael reached Town B 50 minutes earlier than David. When Michael reached Town B, David had travelled 4/5 of the journey and was 75 Km away from Town B.
a) What was the distance between Town A and Town B?
b) How many Kilometres did David travel in 1 hour?
c) What was the time taken by Michael to travel from Town A to Town B?

Q1)
When Lin reaches the halfway mark, Mei is 3.5km ahead of her. This means that Mei reached the halfway mark, (3.5km/ 20km/h) = 10.5 minutes before Lin.
When Lin finished her race, Mei would have finished 21 minutes earlier.
Lin reached the finishing line 21 minutes after 10.45am => 11.06am

Q2)
Pls check for typo error

[Dharma]

Almighty:

Thank u very much for the reply but,Very sorry Dharma.I Still cannot understand the things written in red. Can u plssss clarify?

Dharma:

[quote=\"Almighty\"]One problem.... Please help!!

Two identical containers X and Y have sugar and rice in the ratio 1 : 3 and 2:5 respectively. Tank Z contains some rice only. All the sugar in both containers are put into tank Z. The ratio of the sugar to the rice in tank Z is 3:5. How much sugar is in container X at first if there are 500 g of rice in Tank Z?

Tank X
s:r
1:3 why DID U MULTIPLY BY 7 ?

Tank Y
S :R
2:5 why DID U MULTIPLY BY 4

Tank X
S : R = 7 : 21

Tank Y
S : R = 8 : 20
Amt of S in
Tank Z = 7u + 8u = 15u

Tank Z
S : R = 3 : 5 = 15 : 25

25p = 500g
15p = 15u = 300g
1u = 20g
7u = 140g (Amt of sugar in Tank X)

# Use assumed that 5 parts(rice) in Tank Z = 500g. That is where u went wrong

[/quote]Tank X and Y are IDENTICAL containers. So, total qty of sugar and rice must be the same in both containers. (i.e. 28u).

[YLH88]

Hi all,


Need help with the below speed questions

1) PeiHwa P6 SA1 2009 Paper 2 Qn 4
Auntie Melanie is walking on the platform of an MRT station at 120 m/min.
A train overtakes her completely in 25 seconds.
The length of the train is 300 metres.
How fast is the train ?
(Ans : 14 m/s)

2) PeiHwa P6 SA1 2009 Paper 2 Qn 13
A lorry left Happy Town for Bayview Town at 60 km/h.
Two hours later, a sports car travelling at 140 km/h left Happy Town for Bayview Town too.
The sports car caught up with the lorry at a distance of 20 km away from Bayview Town.
Find the distance between the two towns.
(Ans : 230 km)

Thank you very much!

[Vanilla Cake]

YLH88:

1) PeiHwa P6 SA1 2009 Paper 2 Qn 4

Auntie Melanie is walking on the platform of an MRT station at 120 m/min.
A train overtakes her completely in 25 seconds.
The length of the train is 300 metres.
How fast is the train ?

[MRT Train]---50m--->-----300m---->
[A.Melanie]---50m--->

120m/min = 2 m/sec (Divide 120m by 60)
In 25 seconds, Auntie Melanie walked = 2 m/sec x25 seconds = 50 m
In 25 seconds, MRT train travelled = 50m+300m =350 m where 300 m is the length of train
Average speed of train = 350m divided by 25 seconds = 14 m/s

YLH88:

2) PeiHwa P6 SA1 2009 Paper 2 Qn 13
A lorry left Happy Town for Bayview Town at 60 km/h.
Two hours later, a sports car travelling at 140 km/h left Happy Town for Bayview Town too.
The sports car caught up with the lorry at a distance of 20 km away from Bayview Town.
Find the distance between the two towns.

Use common distance and the relationship between speed and time (inverse ratio) concept

Ratio of speed
Lorry : Car
60 : 140
3 : 7

Ratio of time
Lorry : Car
7 : 3

Difference in time = (7-3)units = 4 units
4 units = 2 hours
1 unit = 0.5 hour
7 units = 3.5 hours (Time travelled by lorry)

Distance travelled by lorry = 60 km/hx3.5 hours = 210 km
Distance between the two towns = (210+20) km = 230 km

OR

Headstart by lorry = 60 km/h x2 hours = 120 km
Difference in speed = (140-60) km/h = 80 km/h
120 km divided by 80 km/h = 1.5 hours
Distance travelled by car in 1.5 hours to catch up with lorry = 1.5x140=210km
Distance between the two towns= (210+20)km = 230 km

[YLH88]

Hi VC,


Thank you very much for the solution!!

Your school term starting next week too ? Enjoy your last week of holiday :lol:

[Almighty]

Hi dharma,

Thank u for yr explanation for the "Identical Tank" problem n other speed problem.
Regarding the typo error, i edited there again. Pls help on tht too.