Quantitative Aptitude प्रश्न और उत्तर का अभ्यास करें

प्र: A box contains 5 green, 4 yellow and 5 white pearls. Four pearls are drawn at random. What is the probability that they are not of the same colour ? 2007 0

  • 1
    11/91
    सही
    गलत
  • 2
    4/11
    सही
    गलत
  • 3
    1/11
    सही
    गलत
  • 4
    90/91
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 4. "90/91"
व्याख्या :

Answer: D) Option D Explanation: Let S be the sample space. Then,n(s) = number of ways of drawing 4 pearls out of 14 = C414 ways = 14×13×12×114×3×2×1= 1001 Let E be the event of drawing 4 pearls of the same colour.Then, E = event of drawing (4 pearls out of 5) or (4 pearls out of 4) or (4 pearls out of 5)   ⇒C15+ C44+ C15 = 5+1+5 =11  P(E) = n(E)n(S)=111001=191      Required probability = 1-191=9091

प्र: The top and bottom of a tower were seen to be at angles of depression 30° and 60° from the top of a hill of height 100 m. Find the height of the tower ? 1997 1

  • 1
    42.2 mts
    सही
    गलत
  • 2
    33.45 mts
    सही
    गलत
  • 3
    66.6 mts
    सही
    गलत
  • 4
    58.78 mts
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 3. "66.6 mts"
व्याख्या :

Answer: C) 66.6 mts Explanation: From above diagramAC represents the hill and DE represents the tower Given that AC = 100 m angleXAD = angleADB = 30° (∵ AX || BD ) angleXAE = angleAEC = 60° (∵ AX || CE) Let DE = h Then, BC = DE = h, AB = (100-h) (∵ AC=100 and BC = h), BD = CE tan 60°=AC/CE => √3 = 100/CE =>CE = 100/√3 ----- (1) tan 30° = AB/BD => 1/√3 = 100−h/BD => BD = 100−h(√3)∵ BD = CE and Substitute the value of CE from equation 1 100/√3 = 100−h(√3) => h = 66.66 mts The height of the tower = 66.66 mts.

प्र: Three strategies P, Q and R have been initiated for cost cutting in a company producing respectively 20%, 30% and 10% savings. Assuming that they operate independently, what is the net saving achieved ? 1997 0

  • 1
    49.6%
    सही
    गलत
  • 2
    50.4%
    सही
    गलत
  • 3
    33.67%
    सही
    गलत
  • 4
    66.66%
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 1. "49.6%"
व्याख्या :

Answer: A) 49.6% Explanation: As these three strategies P, Q and R are independent so these will cut cost one after the other.If initial cost is Rs 100, then20% cost is cut after initializing strategy P, then cost will remain 80% = 80further 30% cost is cut after strategy Q, then cost will remain 70% of 80 = 56further 10% cost is cut after strategy R, then cost will remain 90% of 56 = 50.4 Thus final cost remains 50.4 % of the original cost. Hence net saving is 100 - 50.4 = 49.6 %.

प्र: The first 8 alphabets are written down at random. what is the probability that the letters b,c,d,e always come together ? 1997 0

  • 1
    1/7
    सही
    गलत
  • 2
    8!
    सही
    गलत
  • 3
    7!
    सही
    गलत
  • 4
    1/14
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 4. "1/14"
व्याख्या :

Answer: D) 1/14 Explanation: The 8 letters can be written in 8! ways.n(S) = 8!Let E be the event that the letters b,c,d,e always come together when the first 8 alphabets are written down.Now the letters a, (bcde), f, g and h can be arranged in 5! ways.The letters b,c,d and e can be arranged themselves in 4! ways.n(E) = 5! x 4!Now, the required P(E) = n(E)/n(S) = 5! x 4!/8! = 1/14Hence the answer is 1/14.

प्र: If the sum of two numbers is 55 and the H.C.F. and L.C.M. of these numbers are 5 and 120 respectively, then the sum of the reciprocals of the numbers is equal to ? 1996 0

  • 1
    13/125
    सही
    गलत
  • 2
    14/57
    सही
    गलत
  • 3
    11/120
    सही
    गलत
  • 4
    16/41
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 3. "11/120"
व्याख्या :

Answer: C) 11/120 Explanation: Let the numbers be a and b.We know that product of two numbers = Product of their HCF and LCMThen, a + b = 55 and ab = 5 x 120 = 600.=> The required sum = (1/a) + (1/b) = (a+b)/ab=55/600 = 11/120

प्र: A man can row 6 kmph in still water. When the river is running at 1.2 kmph, it takes him 1 hour to row to a place and back. What is the total distance traveled by the man ? 1996 0

  • 1
    4.58 kms
    सही
    गलत
  • 2
    6.35 kms
    सही
    गलत
  • 3
    5.76 kms
    सही
    गलत
  • 4
    5.24 kms
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 3. "5.76 kms"
व्याख्या :

Answer: C) 5.76 kms Explanation: Speed in still water = 6 kmph Stream speed = 1.2 kmph Down stream  = 7.2 kmph Up Stream = 4.8 kmph x/7.2 + x/4.8 = 1 x = 2.88 Total Distance  = 2.88 x 2 = 5.76 kms

प्र: A person says that his son is 5 times as old as his daughter and his wife is 5 times older than his son and he is twice the age of his wife . The sum total of all the ages equals the age of the grand mother who celebrated her 81st birthday today. How old was his son? 1994 0

  • 1
    50 yrs
    सही
    गलत
  • 2
    25 yrs
    सही
    गलत
  • 3
    72 yrs
    सही
    गलत
  • 4
    40 yrs
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 1. "50 yrs"
व्याख्या :

Answer: A) 50 yrs Explanation: Let the daughter age be 'x'Therefore, Son age = 5x, Mother age = 25x, Person age = 50x. Thus we get, x+5x+25x+50x = 8181x = 81x = 1 Daughter's age = 1, Son's = 5, Mother's = 25, Person's age = 50.

प्र: The sum of three consecutive odd numbers is 93. What is the middle number? 1993 0

  • 1
    31
    सही
    गलत
  • 2
    33
    सही
    गलत
  • 3
    29
    सही
    गलत
  • 4
    27
    सही
    गलत
  • उत्तर देखें
  • Workspace

उत्तर : 1. "31"
व्याख्या :

Answer: A) 31 Explanation: Let the three consecutive odd numbers be x, x+2, x+4 Then, x + x + 2 + x + 4 = 93 => 3x + 6 = 93 => 3x = 87 => x = 29 => 29, 31, 33 are three consecutive odd numbers.   Therefore, the middle number is 31.

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई

  त्रुटि की रिपोर्ट करें

कृपया संदेश दर्ज करें
त्रुटि रिपोर्ट सफलतापूर्वक जमा हुई