Questions

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series 
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series 
24 - 5 = 19
19 - 5 = 14...

1113122110

In given series 2nd number gives number of  which digits present in the 1st number and so on continues for 3rd ,4th,...

Here 1st no. has only one zero, so  2nd no. is 10 and 2nd no. has one 1 and one 0,so 3rd no. is 1110, so like that 5th no. has one 1,one 3,one 2,two 1's and one 0.So the next no. is 1113122110. 

Canada has the longest coastline than any other countries in the world. It measures 1,51,020 miles long approximately. Norway, Indonesia, Greenland and Russia being in 2, 3, 4 and 5th places.

World Population day is an annual event, observed on July 11 every year, which seeks to raise awareness of global population issues. 

Yes, all the above given sentences have an interjection.

1. Hey ! is an interjection in the sentence , Hey!, where did I park my car? 

2. Well is an interjection in the sentence, Well!, that's a relief.

3. Oh! is an interjection in the sentence , Oh!, now I remember where i put my wallet.