Periyar University 2008 B.E Electronics

80) Ram singh goes to his office in the city every day from his suburban house. His driver Mangaram drops him at the railway station in the morning and picks him up in the evening. Every evening Ram singh reaches the station at five o'clock. Mangaram also reaches at the identical time. 1 day Ram singh started early from his office and came to the station at four o'clock. Not wanting to wait for the car he begins walking home. Mangaram begins at normal time, picks him up on the way and takes him back house, half an hour early. How much time did Ram singh walked?




81) two trees are there. 1 grows at 3/5 of the other. In four years total growth of the trees is eight ft. what growth will smaller tree have in two years.

Sol: THE BIG TREE GROWS 8FT IN four YEARS=>THE BIG TREE GROWS 4FT IN two YEARS.WHEN WE DIVIDE 4FT/5=.8*3=>2.4

four (x+ (3/5) x) =88x/5=2x=5/4

After two years x= (3/5)*(5/4)*2 =1.5 (less than two feet)





82) There is a 6 digit code. Its 1st 2 digits, multiplied by three provide all ones. And the next 2 digits multiplied by six provide all twos. Remaining 2 digits multiplied by nine provide all threes. Then what is the code?

Sol: presume the digit xx xx xx (six digits)


First 2 digit xx * 3=111

xx =111/3=37

(First 2 digits of one is not divisible by three so we can use 111)

Second 2 digit xx*6=222

xx=222/6=37

(First 2 digits of two is not divisible by six so we can use 222)

Third 2 digit xx*9=333

xx=333/9=37

(First 2 digits of three is not divisible by nine so we can use 333)







83) There are four balls and four boxes of colors yellow, pink, red and green. Red ball is in a box whose color is identical as that of the ball in a yellow box. Red box has green ball. In which box you obtain the yellow ball?

Sol: Yellow box can have either of pink/yellow balls.


if we put a yellow ball in "yellow" box then it would imply that "yellow" is also the color of the box which has the red ball(because according two d question,d box of the red ball n the ball in the yellow box have identical color)

Thus this possibility is ruled out...

Therefore the ball in yellow box must be pink, hence the color of box contain in red ball is also pink....

Earning:   Approval pending.