1
GATE CSE 2005
MCQ (Single Correct Answer)
+1
-0.3
Let $$f$$ be a function from a set $$A$$ to a set $$B$$, $$g$$ a function from $$B$$ to $$C$$, and $$h$$ a function from $$A$$ to $$C$$, such that $$h\left( a \right) = g\left( {f\left( a \right)} \right)$$ for all $$a \in A$$. Which of the following statements is always true for all such functions $$f$$ and $$g$$?
A
$$g$$ is onto $$ \Rightarrow $$ $$h$$ is onto
B
$$h$$ is onto $$ \Rightarrow $$$$f$$ is onto
C
$$h$$ is onto $$ \Rightarrow $$ $$g$$ is onto
D
$$h$$ is onto $$ \Rightarrow $$ $$f$$ and $$g$$ are onto
2
GATE CSE 2005
MCQ (Single Correct Answer)
+2
-0.6
Let f: $$\,B \to \,C$$ and g: $$\,A \to \,B$$ be two functions and let h = fog. Given that h is an onto function which one of the following is TRUE?
A
f and g should both be onto functions
B
f should be onto but g need not be into
C
g should be onto but f need not be onto
D
both f and need not be onto
3
GATE CSE 2005
MCQ (Single Correct Answer)
+2
-0.6
Box P has 2 red balls and 3 blue balls and box Q has 3 red balls and 1 blue ball. A ball is selected as follows: (i) select a box (ii) choose a ball from the selected box such that each ball in the box is equally likely to be chosen. The probabilities of selecting boxes P and Q are 1/3 and 2/3, respectively. Given that a ball selected in the above process is a red ball, the probability that it came from the box P is:
A
4/19
B
5/19
C
2/9
D
19/30
4
GATE CSE 2005
MCQ (Single Correct Answer)
+1
-0.3
A bag contains 10 blue marbles, 20 green marbles and 30 red marbles. A marble is drawn from the bag, its colour recorded and it is put back in the bag. This process is repeated 3 times. The probability that no two of the marbles drawn have the same colour is
A
1/36
B
1/6
C
1/4
D
1/3