Periyar University 2008 B.E Electronics

(5) 1-1

Ans: 5.

70) two oranges, three bananas and four apples cost Rs.15. three oranges, two bananas, and one apple costs Rs 10. What is the cost of three oranges, three bananas and three apples?

Sol: 2x+3y+4z=15

3x+2y+z=10

Adding

5x+5y+5z=25

x+y+z=5 that is for one orange, one banana and one apple requires 5Rs.

So for three orange, three bananas and three apples require 15Rs.

i.e. 3x+3y+3z=15


Ans: 15





71) In 8*8 chess board what is the total number of squares refers odele discovered that there are 204 squares on the board .We obtained that you would add the various squares

= one + four + nine + 16+ 25 + 36 + 49 + 64. =204




Also in 3*3 tic tac toe board what is the total no of squares

Ans: 14 i.e. 9+4(bigger ones) +1 (biggest one)







If you get 100*100 board just use the formula the formula for the sum of the 1st n perfect squares is



n x (n + 1) x (2n + 1)


______________________


six





72) 1 fast typist kind a few matter in 2hr and a different slow typist kind the identical matter in 3hr. If both do combine in how much time they will finish.

Sol: Faster 1 can do 1/2 of work in 1 hour slower 1 can do 1/3 of work in 1 hour both they do (1/2+1/3=5/6) the work in 1 hour. So work will b finished in 6/5=1.2 hour

i e one hour 12 min.


Ans: one hour 12 min.





73)If Rs20/- is available to pay for typing a research report & typist A produces 42 pages and typist B produces 28 pages. How much should typist A receive?

Sol: obtain 42 % of 20 rs with respect to 70 (i.e. 28 + 42)

==> (42 * 20)/70 ==> 12 Rs

Ans: 12 Rs





74) In a few game 139 members have participated every time 1 fellow will get bye what is the number of matches to select the champion to be held?

Ans: 138 matches

(Explanation: since 1 player gets a bye in every round, he will reach the finals of the tournament without playing a match.

Earning:   Approval pending.