Kalpesh Sharma

***. A person with some money spends 1/3 for cloths, 1/5 of the remaining for food and 1/4 of the remaining for travel. He is left with Rs 100. How much did he have with him in the beginning?

Ans. 250 Ex. (x/3)+(2x/15)+(8x/60)+100=x

***. Mr. x (got award in 1971) died when his age was 1/59th the year of birth. What was his date of birth?

Ans. 1947 Ex. X+(X/59) > 1971 so X > 1938 Then by trial and error.

***. Grass grows equally thick and in a uniform rate. It takes 24 days for 70 cows and 60 days for 30 cows to eat the whole of the grass. How many cows are needed to eat the grass in 96 days?

Ans. 20
g - grass at the beginning
r - rate at which grass grows, per day
y - rate at which one cow eats grass, per day
n - no of cows to eat the grass in 96 days
g + 24*r = 70 * 24 * y
g + 60*r = 30 * 60 * y
g + 96*r = n * 96 * y
Solving, n = 20.

Ex. From first two equations convert g and r into terms of y. Then put it in equation 3.

***. There N stations on a railroad. After adding X stations on the rail route 46 additional tickets have to be printed. Find N and X.

Ans. x=2 and N=11 Initially, N (N-1) = t after adding, (N+X)(N+X-1) = t+46

***. There are some chickens in poultry. They are fed with corn. One sack of corn will come for 9 days. The farmer decides to sell some chicken and wanted to hold 12 chickens with him. He cuts the feed by 10% and sack of corn comes for 30 days. So initially how many chicken are there?

Ans. 36

Ex. Let there were originally N chickens.
Corn eaten by 1 chicken in 1 day = 1/(N*9)
After, Corn eaten by 1 chicken in 1 day = 1/(12*30) = 1/360

1/(N*9) = 1/360 + ((1/360)*0.1)