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- Question
- For what value of k, the equation x 2 + 2(k - 4) x + 2k = 0 has equal roots?
Options- A. 6 and 4
- B. 8 and 2
- C. 10 and 4
- D. 12 and 2
- Correct Answer
- 8 and 2
ExplanationGiven equation is
x2 + 2(k - 4)x + 2k = 0
On comparing with ax2 + bx + c = 0
Here, a = 1, b = 2(k -4), c = 2k
Since, the root are equal, we have D = 0.
b2 - 4ac = 0
? 4(k - 4)2 - 8k = 0
4(k2 + 16 - 8k) - 8k = 0
? 4k2 + 64 - 32k - 8k = 0
? 4k2 - 40k + 64 = 0
? k2 - 10k + 16 = 0
? k2 - 8k - 2k + 16 = 0
? k(k - 8) -2 (k - 8) = 0
? (k - 8) (k - 2) = 0
Hence, the value of k 8 or 2. - 1. In a race of 600 m, A can beat B by 60 m and in a race of 500 m, B can beat C by 50 m. By how many meter will A beat C in a race of 400 m?
Options- A. 78 m
- B. 56 m
- C. 76 m
- D. 86 m Discuss
- 2. 0.15 / (0.5 / 15) =?
Options- A. 4.5
- B. 45
- C. 0.03
- D. 0.45 Discuss
- 3. For any integers a and b with HCF (a, b) = 1, what is HCF (a + b, a - b) equal to?
Options- A. It is always 1
- B. It is always 2
- C. Either 1 or 2
- D. None of the above Discuss
- 4. 5358 x 51 =?
Options- A. 273258
- B. 273268
- C. 273348
- D. 273358 Discuss
- 5. Which of the following numbers is divisible by each one of 3, 7, 9 and 11?
Options- A. 639
- B. 2079
- C. 3791
- D. 37911
- E. None of these Discuss
- 6. If the total sales for a business in a certain year were ? 132000. What were the sales in june, if june sales were half the monthly average?
Options- A. ? 8400
- B. ? 7200
- C. ? 5500
- D. ? 6300 Discuss
- 7. If 0.8 x A = 0.09 x B, then find A : B.
Options- A. 9 : 80
- B. 3 : 80
- C. 80 : 9
- D. 7 : 80 Discuss
- 8. A 4% stock yield 5%. The market value of the stock is?
Options- A. Rs. 125
- B. Rs. 80
- C. Rs. 99
- D. Rs. 109 Discuss
- 9. The product of 3.5413 x 2.1 is
Options- A. 7.44673
- B. 7.43673
- C. 7.53673
- D. None of these Discuss
- 10. Maganlal, a worker, makes an article in every 2/3h. If he works for 7 1/ 2h, then how many articles will he make?
Options- A. 111/4
- B. 111/3
- C. 112/6
- D. 112/5 Discuss
More questions
Correct Answer: 76 m
Explanation:
If A runs 600 m, B runs 600 - 60 or, 540 m.
If A runs 400 m, B runs = 540 x 400 / 600 = 360 m.
Now, when B runs 500 m, C runs 500 - 50 = 450 m.
? When B runs 360 m, C runs = 450 * 360 / 500 = 324 m
? A beats C by 400 - 324 = 76 m.
Correct Answer: 4.5
Explanation:
Let Y = 0.15 / (0.5 / 15)
= (15/100) / [(5/100) / 15)
= 4.5
Correct Answer: Either 1 or 2
Explanation:
Putting arbitrary values of a and b.
IIIustration 1:
Let a = 9 and b = 8
HCF (8 + 9, 9 - 8)
HCF (17, 1) = 1
IIIustration 2:
Let a = 23 and b =17
HCF (17 + 23, 23 -17)
HCF ( 40, 6) = 2
Hence, HCF (a + b, a - b) can either be 1 or 2.
Correct Answer: 273258
Explanation:
| 5358 x 51 | = 5358 x (50 + 1) |
| = 5358 x 50 + 5358 x 1 | |
| = 267900 + 5358 | |
| = 273258. |
Correct Answer: 2079
Explanation:
639 is not divisible by 7
2079 is divisible by each of 3, 7, 9, 11.
Correct Answer: ? 5500
Explanation:
Monthly sale = yearly sale / 2
= 132000 / 2
= ? 11000
June's sale = monthly sale / 2
= 11000 / 2
= ? 1000
Correct Answer: 9 : 80
Explanation:
Given that 0.8 x A = 0.09 x B
? A/B = 0.09/0.8 = 9/80
? A : B = 9 :80
Correct Answer: Rs. 80
Explanation:
For an income of Rs. 5, investment = Rs. 100
For an income of Rs. 4, investment = Rs. (100/5) x 4 = Rs. 80
Correct Answer: 7.43673
Explanation:
For the product of 3.5413 x 2.1
Consider 35413 x 21 = 743673
Total decimal places = 4 + 1
? 3.5413 x 2.1=7.43673
Correct Answer: 111/4
Explanation:
? In 2/3h, 1 article is made.
? In 1h, 3/2 article are made.
? In 71/2 = 15/2h, 3/2 x 15/2 = 45/4 article are made.
? Required articles = 45/4 = 112/4
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