Each of three botanists made a hypothesis regarding specimens of a par

1st: curly -> long/purple/both
2nd: long -> flat/round/both
3rd: No curly/flat/both -> purple

Base on this: 3rd hypothesis conflicts with 1st on the case curly -> purple. Therefore, one of these Hypotheses or both might be incorrect
1st is incorrect when curly -> NO long OR NO Purple
3rd is incorrect when curly/flat/both -> purple

If blank 1 curly, blank2 NO long, and 3rd is correct NO curly-> purple, then curly -> NO long OR NO Purple => 1st is incorrect

­I'll add my 2 cents on it. Let's denote curly stems -> cs long roots -> lr purple flowers ->pf flat leaves -> fl.

Gathering on a table the assumptions of B1,B3 (since they have most elements in common) and we use + for having and - for not having (see the table below) we can see that for all 4 elements apart from cs and lr, both botanists agree on having or not having. So, these two (cs,lr) will fill in the blanks. If it has cs but not lr then the first botanist is mistaken. But also, if it has lr but not cs then the last one is wrong. We choose the first one (the highlighted) because in the statements given the cs is in the if clause whereas the lr in the result clause?

ScottTargetTestPrep manasp35 KarishmaB chetan2u
B1 B3
cs + +

fl - -

pf + +

lr + -­

­The key is to treat the individual hypotheses as combined information when looking for the correct answer. Since B1 and B3 combined implies that if a plant has curly stems- it will have long roots only. 

Hence, if a plant has curly stems but not long roots- that would make hypothese of B1 invalid.

1: If C => P or L

2: If P => F or R

3: If C => not P
....If F => not P

==> 1 and 3 sound conflicting
==> It might be related to whether C and P co-exist

So if the specimen has C
=> Then it has either L or P

(i) If C but not P
=> it must be C + L
=> no contrast with any other statement

(ii) If C but not L
=> it must be C+P
=> Constrast with Botanist 3's statement

Any two part questions will have a total of 10 combinations, only some of which make sense. When I counter these kind of questions, instead of thinking to pinpoint an exact pair, I always go through the 10 combinations. It's easier to spot the wrong pair than to spot the right pair right of the bat. This technique allows me to average ~1.5-2 minutes per TPA question.

Botanist 1: Any individual specimen possessing the gene for curly stems has either the gene for long roots or the gene for purple flowers, or both.
Botanist 2: Any individual specimen possessing the gene for long roots has either the gene for flat leaves or the gene for round seeds, or both.
Botanist 3: No individual specimen that possesses either the gene for curly stems or the gene for flat leaves or both has the gene for purple flowers.
The discovery of an individual specimen of the plant species in question having the gene for __1__ but NOT the gene for __2__ would show that at least one of the three hypotheses described is incorrect.

Here are the 10 combos:
curly stems - flat leaves: not against the hypothesis, as curly stem could have round seed, and not necessarily flat leaves --> eliminate
curly stems - long roots: correct, as we know curly stem can have either long root or purple flowers or both (according to Botanist 1), but according to Botanist 3, curly stem cannot have purple flower. That leaves us with the only choice: curly stem must have long root. And now, if the curly stems don't even have the long root, then that's a big paradox.
curly stems - purple flowers: not against the hypo - it's actually the idea of Botanist 3. --> eliminate
curly stems - round seeds: not against the hypothesis, as curly stem could have flat leaves, and not necessarily round seeds --> eliminate
and so on...

So if we say that C cannot have LR:

So then:
Botanist 1 says it must have PF

But:
Botanist 2 says it cannot have PF

So then one of them must be wrong