MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Probability

Six persons t...

Question

Six persons try to swim across a wide river. It is known that on an average, only three persons out of the ten are successful in crossing the river. What is the probability that at most four of the six persons will cross river safely?

Open in App

Solution

$P (c r o s s i n g t h e r i v e r) = 0.3 P (a t m o s t 4 w i l l c r o s s) = 1 - P (5 o r 6 c r o s s e d s a f e l y) P = 1 - {0.3}^{5} (0.7 + 0.3) = 1 - 0.00243 P = 0.99757$

Suggest Corrections

thumbs-up

0

Similar questions

2 k m

wide river flowing at the rate

5 k m / h r

. A man can swim is still water

10 k m / h r

. He wants to cross the river along the shorted path. Find-
(a) in which direction should the person swim.
(b) crossing time.

Q. If the probability that a person can swim is

0.4

. Five persons are selected randomly to jump into a river, then the probability that

2

of them survive is

(a) \frac{144}{625} (b) \frac{232}{625}

(c) \frac{108}{125} (d) \frac{216}{625}

Q. A river is flowing in a south-east direction. A person wants to cross this river in the shortest possible duration. What is the direction in which he should swim in the river?

Q. A man can swim in still water at a speed of

3 k m / h

. He wants to cross a river that flows at

2 k m / h

and reach the point directly opposite to his starting point.
(a) In which direction should he try to swim (that is, find the angle his body makes with the river flow)?
(b) How much time will he take to cross the river if the river is

500 m

Q. A man is trying to cross a river to cross a river flowing at a speed of

5 m s^{- 1}

to least possible displacements by swimming at an angle of 143 to the stream. The drift he suffers when he is crossing the same river in least possible time is (Width of river = 1 km)

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Probability

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Standard X Mathematics

Join BYJU'S Learning Program

CrossIcon