Aptitude - Area - Discussion

@ : Home > Aptitude > Area > General Questions - Discussion

"In the middle of difficulty lies opportunity."

- Albert Einstein

10.

What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?

[A].	814	[B].	820
[C].	840	[D].	844

Answer: Option C

Explanation:

Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm.

Area of each tile = (41 x 41) cm².

Required number of tiles = 1517 x 902 = 814.

41 x 41

Idk said: (Fri, Sep 10, 2010 03:53:33 PM)

Can anyone explain the logic why HCF is used ?

Shanthi said: (Sat, Oct 23, 2010 04:17:21 AM)

Length and breath are given. So area of rectangle is lxb. Also they are askin to find the least no. of square tiles. For square tiles we need the area. In a square al the sides are equal. Hcf is the highest common factor of 1517 and 902. So 41 is the hcf n area of square is 41^2. So divide area of rect by area of square.

Vivek Jain said: (Fri, Jul 1, 2011 09:40:19 AM)

Hi divya! I am also not getting why hcf is used. If you have got the answer then reply me please.

Shashank said: (Mon, Aug 8, 2011 05:36:28 PM)

Since hcf is a prime no. , how we can find the hcf of such big numbers. For those who want to know why hcf::. As we have to set square tiles in a rect. Floor that's why we need a comman factor for both length and breadth so that the no. Of tiles is a natural number but not a fraction!

Vinod Mishra said: (Sat, Aug 13, 2011 11:16:25 PM)

Hi I m not getting the hcf of 1517 and 902 is 41. How it has calculated ?

Ibrahimsha said: (Thu, Sep 29, 2011 06:05:32 PM)

902)1517(1 902 ------ 615)902(1 615 --- 287)615(2 574 --- 41)287(7 287 --- 0 By this method of successful division, remainder goes 0. Last divisor forms your req. HCF.... So 41 is ur HCF :-)

Balajisingh said: (Tue, Jan 10, 2012 12:03:31 PM)

Imbrhimsha now I'm clear with HCF thank you.

Vani Varma said: (Tue, Feb 7, 2012 12:47:25 PM)

Thank you shanthi, shasank and Ibrahimsha.