[Spoiler Alert] PPP2 Quant Query

[sarahthussain]

Hello,

Would someone be able to help me with the following:

For the first one, I selected A as the answer and used the choosing numbers approach. I first did x = 3 and y = -1 and then x = 3 and y = -2. In both cases A was greater than B.

For the second one, I actually just couldn’t figure out how to approach it.

F

[Leaderboard]

@sarahthussain

For the first one, I selected A as the answer and used the choosing numbers approach. I first did x = 3 and y = -1 and then x = 3 and y = -2. In both cases A was greater than B.

Try a value of y close to 0.

@sarahthussain

For the second one, I actually just couldn’t figure out how to approach it.

Put it this way: show that he can take 24 pencils and not have a single pencil of the fifth colour.

[sarahthussain]

@Leaderboard

Try a value of y close to 0.

ohhhh that makes a lot of sense now. In general, when choosing numbers should we be looking at extremes? For example, a very big x value and a very small y value etc?

@Leaderboard

Put it this way: show that he can take 24 pencils and not have a single pencil of the fifth colour.

I am sorry I am still not following

[Leaderboard]

@sarahthussain

In general, when choosing numbers should we be looking at extremes? For example, a very big x value and a very small y value etc?

For a QC question, that’s often a good option.

@sarahthussain

I am sorry I am still not following

Let’s look at the question again. We want to take pencils from the box. As with the previous problem, this is again a question where we need to look at extremes.

Suppose he takes

• 6 pencils of the first colour
• 6 pencils of the second colour
• 6 pencils of the third colour
• 6 pencils of the fourth colour

Notice that

• he has take 24 colours in total, and
• we haven’t used a single pencil of the fifth colour

Can you extend this to solve the original problem?