Question

Twenty caravans are travelling across the desert one day apart. The
first caravan reaches the oasis and the camel drank half of the water in the
pool. On the second day, the second caravan reaches the oasis and the
camel drank one third of the water that was left. On the third day the camel
in the third caravan drank one quarter of the water that was left. On the
first day the pool contained 1050 sq.metre of water. How much water was
left after the twenty caravan passed through?

Answer 1

let the original amount of water present in oasis be x m².
then,
amount of water drank by first camel =
½x
water left = ½x
then
amount of water drank by second camel = ½•⅓x = 1/6x
water left = ½x – 1/6x = ⅓x
then
amount of water drank by third camel =
¼•⅓x = 1/12x
water left = ⅓x – 1/12x = 1/4x

from here we can see that on n-th day the camel drank 1/(n+1) part of water that was left and amount of water that WAS left is (1/n)x.
SO THE AMOUNT OF WATER THAT IT DRiNK IS [ (1/n) - (1/(n)(n+1)) ] x = x/(n+1)

so,
on 20 th day,
x/21 = 1050/21 = 50 m² is the amount of water left.

hope it helps you if yes then please mark my answer as brainliest ☺️☺️.

Answer 2

Description:

Twenty caravans are travelling across the desert one day

apart. The first caravan reached the oasis and the camels

drank half of the water in the pool. On the second day, the

second caravan reached the oasis and the camels drank

one-third of the water that was left. On the third day, the

camels in the third caravan drank one -quarter of the

water that was left. On the first day the pool contained

1050 cubic metre of water. How much water was left after

the 20th caravan passed through.

Hint: Observe the pattern and calculate.