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- Question
- Boxes numbered 1, 2, 3, 4 and 5 are kept in a row and they are to be filled with either a red or a blue ball such that no two adjacent boxes can be filled with blue balls Then, how different arrangements are possible, given that all balls of a given colour are exactly identical in all respects?
Options- A. 8
- B. 10
- C. 15
- D. 22
- Correct Answer
- 22
ExplanationTotal number of ways filling the 5 boxes numbered as (1, 2, 3, 4 and 5) with either blue or red balls = 25 = 32
Two adjacent boxes with blue balls can be obtained in 4 ways, i.e., (12), (23), (34) and (45). Three adjacent boxes with blue balls can be obtained in 3 ways i.e., (123), (234) and (345). Four adjacent boxes with blue balls can be obtained in 2 ways i.e., (1234) and (2345) and five boxes with blue balls can be got in 1 way.
Hence, the total number of ways of filling the boxes such that adjacent boxes have blue balls
= (4 + 3 + 2 + 1)
= 10
Hence, the number of ways of filling up the boxes such that no two adjacent boxes have blue balls
= 32 - 10
= 22 - 1. A certain industrial loom weaves 0.128 meters of cloth every second. Approximately how many seconds will it take for the loom to weave 25 meters of cloth?
Options- A. 220
- B. 200
- C. 170
- D. 195 Discuss
- 2. 21 goats eat as much as 15 cows. How many goats eat as much as 35 cows?
Options- A. 38
- B. 49
- C. 37
- D. 41 Discuss
- 3. In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days one cow will eat one bag of husk?
Options- A. 15
- B. 40
- C. 38
- D. 32 Discuss
- 4. On March 1st 2016 , sherry saved ? 1. Everyday starting from March 2nd 2016, he save ?1 more than the previous day . Find the first date after March 1st 2016 at the end of which his total savings will be a perfect square.
Options- A. 17th March 2016
- B. 18th March 2016
- C. 26th March 2016
- D. None of these Discuss
- 5. Tea worth Rs. 126 per kg and Rs. 135 per kg are mixed with a third variety in the ratio 1 : 1 : 2. If the mixture is worth Rs. 153 per kg, the price of the third variety per kg will be:
Options- A. Rs. 169.50
- B. Rs. 170
- C. Rs. 175.50
- D. Rs. 180 Discuss
- 6. Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is:
Options- A. 2 : 3
- B. 4 : 3
- C. 6 : 7
- D. 9 : 16 Discuss
- 7. Two ships leave a port at the same instant. One sails at 30km/hr in the direction N 32° E while the other sails at 20 km/hr in the direction S 58° E. After two hours the ships are distant from each other by.
Options- A. 15?6 Km
- B. 36.5 Km
- C. 20?13 Km
- D. 100 Km Discuss
- 8. A man reads 3/8 of a book on a day and 4/5 of the remainder on the second day. If the number of pages still unread are 40, then how many pages did the book contain?
Options- A. 300
- B. 500
- C. 320
- D. 350 Discuss
- 9. Last year Sahara, Tata, Singhania and Birla each has 250 industries. This year everyone has sold out 10 factories due to the recession of the economy and poor turnout. The average number of industries which of them now has
Options- A. 260
- B. 240
- C. 25
- D. none of these Discuss
- 10. Two train of length 70 m and 90 m are moving in opposite directions at 10 m/s and 6 m/s, respectively. Find the time taken by trains to cross each other .?
Options- A. 10 s
- B. 8 s
- C. 12 s
- D. 16 s Discuss
More questions
Correct Answer: 195
Explanation:
A certain industrial loom weaves 0.128 meters of cloth in 1 second.
A certain industrial loom weaves 1 meters of cloth in 1/0.128 second.
A certain industrial loom weaves 25 meters of cloth in 25 x 1/ 0.128 second.
A certain industrial loom weaves 25 meters of cloth in 195.312 second.
Correct Answer: 49
Explanation:
15 Cows eat as much as 21 Goats.
? 1 Cows eat as much as 21/ 15 Goats.
? 35 Cows eat as much as 21 x 35 / 15 Goats.
? 35 Cows eat as much as 21 x 7 / 3 Goats.
? 35 Cows eat as much as 7 x 7 Goats.
? 35 Cows eat as much as 49 Goats.
Correct Answer: 40
Explanation:
40 cows eat 40 bags of husk in 40 days.
? 1 cows eat 40 bags of husk in 40 x 40 days.
? 1 cows eat 1 bags of husk in 40 x 40 / 40 days.
? 1 cows eat 1 bags of husk in 40 days.
Correct Answer: None of these
Explanation:
According to the question,
Every day adding 1 rs extra to previous day.
Let us assume after n day, total saving will become perfect square.
1 + 2 + 3 + 4 + 5 + 6 +.......................+ tn.
Apply the algebra A.P formula,
sum of total rupees after n days = n(n+1)/2
Hit and trail method, Put the value of n = 2 , 3 , 4, 5 .... and so on to get the perfect square.
If n = 2
n(n+1)/2 = 2 x 3 / 2 = 3 which is not perfect Square.
If n = 3
n(n+1)/2 = 3 x 4 / 2 = 6 which is not perfect Square.
If n = 4
n(n+1)/2 = 4 x 5 / 2 = 10 which is not perfect Square.
If n = 5
n(n+1)/2 = 5 x 6 / 2 = 15 which is not perfect Square.
If n = 6
n(n+1)/2 = 6 x 7 / 2 = 21 which is not perfect Square.
If n = 7
n(n+1)/2 = 7 x 8 / 2 = 28 which is not perfect Square.
If n = 8
n(n+1)/2 = 8 x 9 / 2 = 36 which is perfect Square.
n(n+1)/2 should be a perfect square . The first value of n when this occurs would be for n = 8. thus , on the 8th of March of the required condition would come true.
Correct Answer: Rs. 175.50
Explanation:
| So, their average price = Rs. | ❨ | 126 + 135 | ❩ | = Rs. 130.50 |
| 2 |
So, the mixture is formed by mixing two varieties, one at Rs. 130.50 per kg and the other at say, Rs. x per kg in the ratio 2 : 2, i.e., 1 : 1. We have to find x.
By the rule of alligation, we have:
| Cost of 1 kg of 1st kind Cost of 1 kg tea of 2nd kind | ||
| Rs. 130.50 | Mean Price Rs. 153 |
Rs. x |
| (x - 153) | 22.50 | |
| ∴ | x - 153 | = 1 |
| 22.50 |
⟹ x - 153 = 22.50
⟹ x = 175.50
Correct Answer: 4 : 3
Explanation:
Let us name the trains as A and B. Then,
(A's speed) : (B's speed) = √b : √a = √16 : √9 = 4 : 3.
Correct Answer: 20?13 Km
Explanation:
Let us draw a figure below as per given question.
Let two ships started from point O at the speed of 30 km/hr and 20 km/hr respectively, after two hours they reach at points A and B.
Now, ?NOA = 32° and ?SOB = 58° ,
Then, ?AOB = 180° - (32° + 58°) = 90°
Since ?AOB is a right triangle in which OA = 2 x 30 = 60 km and OB = 2 x 20 = 40 km
Since, AB = ?OA2 + OB2
= ?(60)2 + (40)2
= ?5200
= 20?13
Correct Answer: 320
Explanation:
Let the number of pages be p.
Number of pages read on first day = 3p/8
Remaining pages = p - 3p/8 = (8p - 3p)/8 = 5p/8
Number of pages read on second day = 4/5 x 5p/8 = p/2
Now , remaining pages = p - [ 3p/8 + p/2]
= p - [(3p + 4p)/8] = [p- 7p/ 8]
= [(8p - 7p)/ 8] = p/8
According to the question
p/8 = 40
? p = 40 x 8
? p = 320
Correct Answer: 240
Explanation:
Required average
= Old average - Sold average
= ( 250 ) - ( 10 ) = 240
Correct Answer: 10 s
Explanation:
According to the formula .
Required time = (x + y) / (u + v)
Here, x = 70 m, y = 90 m, u = 10 m/s and v = 6 m/s
? Required time = (70 + 90) / (10 + 6) = 160/16 = 10 s
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