870

[JosefW912]

Might someone please explain how the format works on Question 870? The format doesn't quite seem to make any sense...

[ohthatpatrick]

Ooooh, that's a brutal one.

If you haven't read our chapter on Open Grouping, unfortunately it will be hard to describe what you're looking at there.

The 1 dot, 2 dots, 3 dots notation is a way of showing our brains that all three of the STU options will get used.

Since there are two sets of 1 dot, 2 dots, 3 dots within the first four columns, we know that STU will get used twice in filling those six spots.

i.e. There will be 2 S's, 2 T's, 2 U's involved in filling those six spots with dots on them.

Hence there will be 3 S's, and that's why 2 S's must be false.