GATE CSE 2014 Set 3 | Question: GA-2

Question

If she _______________ how to calibrate the instrument, she _______________ done the experiment.

• A. knows, will have
• B. knew, had
• C. had known, could have
• D. should have known, would have

Answer 1

A. We can use "will have done" to talk about what will have been achieved by a certain moment in time.
e.g. I'll have finished this project by Friday.

So, (A) is not the correct option.

B. If + simple past $\to$ would/ would be
e.g.,

1. If It rained, you would get wet.
2. If I spoke Italian, I would be working in Italy.

So, (B) is not the correct option.

C. If + past perfect $\to$ would have/could have/ would have been
e.g.,
If you had studied harder, you could have passed the exam.

So, (C) is the correct option.

Answer 2

To answer these i normally use the language(even english itself) i am fluent in.
Option C) makes perfect sense , rest do not relate to each other.

Answer 3

A)knows, will have //Present, future

B)knew, had //past past

c)had known, could have//past perfect, perfect conditional 

D)should have known, would have //present, future    

In Type 3 conditional sentence, the tense in the 'if' clause is the past perfect, and the tense in the main clause is the perfect conditional or the perfect continuous conditional.

IF CLAUSE (CONDITION)	MAIN CLAUSE (RESULT)
If + past perfect	perfect conditional or perfect continuous conditional
If this thing had happened	that thing would have happened.

  source: http://www.edufind.com/english-grammar/type-3-conditional/. Thus option c is correct.

Answer 4

“HAD” is used to express things which occur before the happening of the event.

Eg- Had I studied for the exam, today I would be topper.

Similarly, option C is correct