Q2

[DevinD393]

Could someone explain this question in more depth?

[ohthatpatrick]

There are two main ways to get a correct answer on MBT:
1. find an answer that matches a deduction you made
2. eliminate the four wrong answers by showing possible counterexamples.

Let's try #2 first.

A) Does 1 have to come before 2? Can we think of a counterexample where 1 comes later than 2?
2 - 4 - 1 - 0 - 3
Eliminate.

B) does 1 have to come before 3? Could we get 1 later than 3?
2 - 4 - 0 - 3 - 1
Eliminate.

C) does 2 have to come earlier than 3? Can we think of a way to have 3 earlier than 2? Hmm, seems hard to do. This might be right.

D) Can we get 0 to be before 3? Oh, we already did with (B). Eliminate.

E) Can we get 3 to be before 4?
1 - 2 - 3 - 0 - 4
Elimiante


The #1 way of getting Q2 correct has more to do with our setup. When we see that 3rd rule, that the 2nd digit is twice the 1st, we should think about what possibilities we have there.

The only ones we have are
1 - 2 - __ __ __
or
2 - 4 - __ __ __

Because of those "frames", we would know that (C) is correct. Every code we make will start 1 - 2,
or 2 - 4, so the 2 will always be earlier than the 3.