Questions

Improve the bracketed part of the sentence.
Scientists (have developed) an “organ-on-a-chip” platform to study how drugs are transported across the human placental barrier.

Zeolite is

Through photosynthesis at least a half of the total carbon dioxide fixation on earth is carried out by?

In the following question, out of the four alternatives, select the alternative which best expresses the meaning of the idiom/Phrase.
Chicken-hearted

In the following question, the sentence given with blank to be filled in with an appropriate word. Select the correct alternative out of the four and indicate it by selecting the appropriate option.
Virat Kohli added another feather _____ his cap by his wonderful performance in the one day match.

In each of the following questions three statements are given and these statements are followed by two conclusions numbered (1) and (2). You have to take the given three statements to be true even if they seem to be at variance from commonly known facts. Read the conclusions and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.
Statements:

All books are novels.
No novel is a magazine.
All magazines are newspaper.
Conclusions: 

I.No book is a magazine.
II. Some newspaper are novels.

In an examination, 52% candidates failed in English and 42% failed in Mathematics. If 17% failed in both the subjects, then what percent passed in both the subjects?

What is the simplified value of [(sec3x – tan3x)/(sec x – tan x)] – 2 tan2x – sec x tan x?