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3/3 completed correctly.

Last one was tricky since you could interpret it in more than one way. However, due to the lack of specification, I went with the general time taken. A literal 3 days before it was actually completed, and not relative to when it was either all of them or just B and C.

And here,he is preparing us for olympiad

#2 is long-winded. Easier and more intuitive is that Anne goes 24 (12x2) longer in 4 hrs, so the time is 6 (24/4) hrs in which Bob does 48 (60-12) so his speed is 8 (48/6)

Finally😭

I solved all of the questions from your video on my own!!!

My way of solving problem 2 was by seeing the time it took for Alice to reach the 48 km point. We assume both move at constant speed.
While we don’t know the total time it took for them to reach that point, we know that Alice in total moved a distance of 72 kilometres, where 60 kilometres were spent moving forward and 12 were spent moving back. The time it takes for Alice to move is unknown, but we can define it as the full time it takes for both to meet. Bob requires this full time to reach 48 kilometres, while Alice who has already moved 48 kilometres can spend an extra 24 kilometres doing nothing in the time, as the 12 kilometres forward to the 60 metre mark and 12 kilometres back do not change the displacement. This means it takes 2/3 the total time for Alice to make it to the 48 kilometre point, and it takes the full time for Bob to do the same. As speed is inversely proportional to time, we know that we have to use the reciprocal to describe the proportion for Alice’s speed to Bob’s speed, meaning Alice is 3/2 times as fast as Bob
Now from the original equation which was Alice is 4 km per hour faster than Bob. This can be represented as
A = B + 4
We also now know Alice is 3/2 times the speed of Bob so,
A = 3/2B

A=A

B + 4 = 3/2B
Times both sides by 2
2B + 8 = 3B
Simplify to get
8 = B
Which is Bob’s speed

Great one, I solved two, the last one tricked me.

Best Chanel ever

For the filling I go for the common denominstor which is 60 minutes. If we run both taps for 60 minutes we get 3 + 4 = 7 buckets. 60/7 minutes per bucket

nice content! congrats

Nice man these questions are actually amazing
Where do you get it from

Last 2-4 weeks we solved quiestions exactly as q1

I remembered I used to solve these types of questions when I was a kid in standard 5 or 6!!

I wrote this from just looking at the thumbnail, before watching the video.

It will take a lot less than 15 minutes.

If there were 2 of A, it would take half the time, or 7.5 minutes to fill one bucket to the fill line, but B is less efficient than A, so it will take longer. The question is how much less efficient and how much longer will it take?

B is taking 4/3 as much time as A, so it is 3/4 as efficient. In 7.5 minutes A will fill 4/8 of the bucket, while B will only fill 3/8 of the bucket, together they will fill 7/8 of the bucket in 7m 30s, still leaving another 1/8 of the bucket.

A + B = 7/8 of the job in 7m 30s. So how long will it take to finish the job?

It will take 1/7 of that time to fill 1/8 of the bucket, so it will take an additional 1m 4.2857s to fill the bucket. I'm not going to worry about a fraction of a second, so my calculation is that it will take 8 minutes 34 seconds to fill the bucket.

But I'm not sure how to put all that into a mathematical equation.

I thought it was crazy that it would take 14m 40s, so my initial response was: no way is it going to take that long to fill the bucket. I was certain that the math was faulty.

Edit:

But then I saw that the problem was further complicated by faucet A being arbitrarily turned off after only 4 minutes.
In that case only 46.7% of the bucket would be filled after the 4 minutes.

How long would it take faucet B to fill the remainder of the bucket? Well it takes B 20 minutes to fill the entire bucket. So to fill the remaining 53.3% of the bucket would take another 10m 40s.

So yeah, in that case it would take 14 minutes 40 seconds to fill the bucket.

My solution would be to leave faucet A running. Then it would only take 8 minutes 34 seconds to fill the bucket.

I immediately solved the one in the thumbnail. The faucet that fills the bucket in 15 minutes fills it 1/15 full in 1 minute; the other faucet fills it 1/20 full in a minute. We can easily add these fractions, as 60 is the lowest common multiple of 15 and 20: 4/60 + 3/60 = 7/60 of the bucket full in one minute. Therefore it takes 60/7 (or 8 4/7) minutes for both faucets to fill the bucket.

Solved all 3🎉😂

Second seems like Von Neuman answer train an fly.

In our exams we have to do this questions in under 10secs 🎉 ssc CGL

ezz :3 3/3 complete

I tried using a piecewise function for Alice's distance to solve Q2, which worked but it's more complicated

These problems are all velocity = distance / time or rate = work / time or something along those lines, if you just know how rate works and is related to distance or work and time then these are simple problems.