Which of the following variables are discrete?

1. daily temperature of your city

2. sizes of shoes

3. distance travelled by a man

4. time

The class-mark of the class 35-45 is :

1. 35

2. 45

3. 40

4. 42

In the class-intervals 1-10, 11-20, 21-30; the class 11-20 after adjustment is :

1. 0.5-10.5

2. 20.5-30.5

3. 10.5-30.5

4. 10.5-20.5

The class marks of a frequency distribution are 10, 15, 20, 25, …………… The class corresponding to the class mark 15 is :

1. 12.5-17.5

2. 10-20

3. 10.25-17

4. 14-16