Advertisements
Advertisements
प्रश्न
Along a road lie an odd number of stones placed at intervals of 10 m. These stones have to be assembled around the middle stone. A person can carry only one stone at a time. A man carried out the job starting with the stone in the middle, carrying stones in succession, thereby covering a distance of 4.8 km. Then, the number of stones is·
पर्याय
35
15
31
29
Advertisements
उत्तर
31
Explanation:
Let the number of stones = n
The distance between every stone = 10 m
So, here an AP is formed, a = 20, d = 20
`="n"/2[2"a"+("n"-1)"d"]`
Diatance between in both side,
`⇒4800=2("n"/2 2"a"+("n"-1)"d")`
⇒ 4800 = n[2 × 20 + (n − 1)20]
∴ n = 15 (on one side)
Then, the number of stones on both side
= 2 × 15 = 30
∴ Total number of stones
= 30 + 1 (middle stone) = 31
APPEARS IN
संबंधित प्रश्न
A man walks from his house to the Railway station to catch a train, which is running as per schedule. If he walks at 6 km/hr, he misses the train by 9 minutes. However, if he walks at 7 km/hr, he reaches the station 6 minutes before the departure of rain. The distance of his home to the Railway Station is:
A man can row 14 km/hr in still water. ln, the stream flowing with the speed of 10 km/hr he takes 4 hours to move with the stream and come back. Find the distance he rowed the boat.
In a school for midday meal food is sufficient for 250 students for 33 days, if each student is given 125 gm meals. 80 more students joined the school. If the same amount of meal is given to each student, then the food will last for
In a race of 200 m run, A beats S by 20 m and N by 40 m. If S and N are running a race of 100 m with exactly same speed as before, then by how many metres will S beat N?
Neeraj is going to Agra on his bike from Delhi. He overtakes a bus traveling from Delhi to Agra at 4.30 pm. Neeraj reaches Agra at 6 pm. After stopping there for an hour, he starts back towards Delhi and meets the same bus at 7.30 pm which was moving towards Agra at that time. If both the bus and the bike were traveling with uniform speeds on the same route, at what time would the bus reach Agra?
A train passes a 110 m long platform in 40 s and a boy standing on the platform in 30 s. The length of the train is
Two trains of equal length are running on parallel lines in the same direction at 46 km/h and 36 km/h. The faster train passes the slower train in 36 s. The length of each train is
A car travels a distance of x km at a speed of `5 5/9` m/sec and returns at 5m/sec to the starting point. If the total time taken by the car in `7 3/5` hours then the value of x (in km) is:
A car consumes 5.4 litres of petrol to cover 60.48 km, how many kilometers be covered with 22 litres of petrol?
A motor starts with the speed of 70 kmph with its speed increasing every two hours by 19 kmph. In how many hours will it cover 345 kms?
