Q&A - PSLE Math

[superksmum]

Hi help needed!


A tank was half filled with water. More water was added until it was 2/3 full. The ratio of the mass of the tank when it was 1/2 full to the mass of the tank when it was 2/3 full was 7:9.

a) What is the ratio of the volume of water in the tank when it was 1/2 full to the volume of the water went he tank was 2/3 full?

b) the mass of the empty tank was 500g. What was the total mass of the tank and water when the tank was 2/3 full?

[tianzhu]

Michaelia0816:

5) At 10am, Wang set off from Town A for Town B at an average speed of 64 km/h. at the same time, Han set off from Town B for Town A at an speed 25% faster than Wang. they were 144 km apart after 2/3/4 h.

A) How far apart were the two towns?
B) At what time would they pass each other along the way?

Hi

Han’s speed ------ 64*1.25 ------- 80 km/h

In 1 h, Wang and Han covered (64 + 80) ------- 144 km

In 2.75h, they covered (2.75*144) ------ 396 Km

Distance between two towns ------ 396 + 144 ------ 540 km

They met at (2.75+1) or 3.75h from 10 am which is 1.45 pm

Best wishes

[tianzhu]

Michaelia0816:

Ed set off from his home for Town Q at 11.20 am . by 1 pm, he had covered 2/5 of the journey aft travelling at an average speed of 60km/h. After that, he increased his speed by 20% for the rest of the journey.

A) what was the distance from Ed home to town Q?
B) At what time did Ed arrived in Town Q

Hi

From 1120 am to 1pm -------- 1h 40 mins

He covered (60*5/3 ) -------- 100km

2 units------ 100 km

5 units ------- 250 km (Distance from Ed’s home to Q)

Increased speed ------- 72 km/h

150/72 ------ 2h 5 mins

Ed arrived in Town Q at 3.05 pm

Best wishes

[tianzhu]

Michaelia0816:

9)A motorist took 3 h to travel from p to r while a cyclist took 5h20min to travel from s to q. If both of them set off at the same time, how far away from p did they pass by each other?

Hi

Please confirm.

Best wishes

[tianzhu]

Michaelia0816:

Roger took 1/1/3 h to drive from Greenland to pinkcity at an average speedof 0km/h. After this, he increased his speed by 25% and continued driving to redsville for 40 minutes.

A) how far did Roger drive together?
B) find his average speed for the whole journey?

Hi

Please check.

Best wishes

[tianzhu]

Michaelia0816:

Peter set off from x for z at 10.45 am at a uniform speed of 64 km/h. 20 minute later, Dave set off from z to x at the uniform speed and he passed Peter at y.

The distance between x and y is 96km and the distance between y and z is 140km.
A) find the speed at which Dave was travelling?
B) at what time would Dave arrive at x?

Hi

Please confirm, 60 or 64.

Best wishes

[Michaelia0816]

Yes, I confirm, sorry Tianzhu it should be point p to point r and point s to point q! for question 9.

[Michaelia0816]

tianzhu:

Michaelia0816:

4) Town J and Town K were 450km apart. Nancy started to drive from Town J for Town K at 10am. At hour later, Jenny started to drive from Town K for Town J at 75% the average speed of Nancy. they met each other at 1pm along the way.

A) at what speed was nancy driving?
b) How far from Town J did they met each other?

Hi

Start with a simple diagram.

In 1h, Nancy covered 4 units.
In 1h, Jenny covered 3 units.

From 10 am to 11 am, Nancy covered 4 units.

From 11 am to 1 pm, Nancy covered 8 units and Jenny covered 6 units

Total units ------- 18 units
450/18 ------25

4 units ------ 4*25 ------ 100 km/h (Nancy’s speed)

They met at 100+200 or 300 km away from J.

Best wishes

How to find it? Is it 8u---200?

[Michaelia0816]

60.

[tianzhu]

Michaelia0816:

the ratio of a van's speed to that of a car's speed was 3:5. If the van took 1 minutes more to cover a distance of 0.5 km than the car, find the speed of the van in km/h. ( hint: first convert 0.5 km/min to km/h)

Hi

1 min ------- 0.5 km
60 mins -------- 30 km

2 units ------- 30
1 unit ------ 15

Speed of van ------- 3 units ------- 15*3 ----45km/h

Best wishes