Q3 of 23 Page 1

Attempt any three of the following sub questions:

How many three digit natural numbers are divisible by 5?

The three digit natural numbers are from 100 to 999.

The first and last three-digit number divisible by 5 are 105 and 995 respectively.


It is an AP as (105,110,……995)


an = a + (n - 1)d


⇒ 995 = 105 + (n - 1)5


⇒ 890 = (n - 1)5


⇒ 178 = (n - 1)


⇒ n = 179.


There are 179 three digit natural numbers divisible by 5.


More from this chapter

All 23 →
2

Attempt any four of the following subquestions:

Two coins are tossed simultaneously. Write the sample space (S), n(S), the following event A using set notation and n(A), where ‘A is the event of getting at least one head.’

 2

Attempt any four of the following subquestions:

Find the value of k for which the given simultaneous equations have infinitely many solutions:


Kx + 4y = 10;


3x + 2y = 5.

 3

Attempt any three of the following sub questions:

Solve the following quadratic equation by factorization method:


3x2 - 29x + 40 = 0.

 3

Attempt any three of the following sub questions:

Solve the following simultaneous equations by using Cramer’s rule:


3x - y = 7;


x + 4y = 11.