Quantitative Aptitude Practice Question and Answer
8Q: A bag contains 4 red and 3 black balls. A second bag contains 2 red and 4 black balls. One bag is selected at random. From the selected bag, one ball is drawn. Find the probability that the ball drawn is red. 2010 05b5cc7d0e4d2b4197775121d
5b5cc7d0e4d2b4197775121d- 123/42false
- 219/42true
- 37/32false
- 416/39false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "19/42"
Explanation :
Answer: B) 19/42 Explanation: A red ball can be drawn in two mutually exclusive ways (i) Selecting bag I and then drawing a red ball from it. (ii) Selecting bag II and then drawing a red ball from it. Let E1, E2 and A denote the events defined as follows: E1 = selecting bag I, E2 = selecting bag II A = drawing a red ball Since one of the two bags is selected randomly, therefore P(E1) = 1/2 and P(E2) = 1/2 Now, PAE1 = Probability of drawing a red ball when the first bag has been selected = 4/7 PAE2 = Probability of drawing a red ball when the second bag has been selected = 2/6 Using the law of total probability, we have P(red ball) = P(A) = PE1×PAE1+PE2×PAE2 = 12×47+12×26=1942
Q: A person travels from K to L a speed of 50 km/hr and returns by increasing his speed by 50%. What is his average speed for both the trips ? 2010 05b5cc6d8e4d2b4197774e764
5b5cc6d8e4d2b4197774e764- 155 kmphfalse
- 258 kmphfalse
- 360 kmphtrue
- 466 kmphfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "60 kmph"
Explanation :
Answer: C) 60 kmph Explanation: Speed on return trip = 150% of 50 = 75 km/hr. Average speed = (2 x 50 x 75)/(50 + 75) = 60 km/hr.
Q: Pavan and Sravan are two persons. If Pavan works with his actual efficiency and Sravan twice of his actual efficiency then it takes 25 days to complete the work. But If Pavan works twice of his actual efficiency and Sravan with his normal efficiency then the work is completed in 20 days. How many days would it take if Sravan alone works with his actual efficiency (in Days)? 2009 05b5cc6c7e4d2b4197774ded2
5b5cc6c7e4d2b4197774ded2- 150false
- 2100true
- 370false
- 435false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "100"
Explanation :
Answer: B) 100 Explanation: Let the Efficiency of pavan be E(P) Let the Efficiency of sravan be E(S) Here Work W = LCM(25,20) = 100 Now, E(P+2S) = 100/25 = 4 ....(1) E(2P+S) = 100/20 = 5 ....(2) Hence, from (1) & (2) we get E(S) = 1 => Number of days Savan alone work to complete the work = 100/1 = 100 days.
Q: Sneha’s weight is 140% of Veena’s weight. Rina’s weight is 90% of Sana’s weight. Sana weighs twice as much as Veena. If Sneha’s weight is x% of Rina’s weight, then x is equal to: 2007 05b5cc699e4d2b4197774c750
5b5cc699e4d2b4197774c750- 1596/9false
- 2605/9false
- 3645/9false
- 4700/9true
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "700/9"
Explanation :
Answer: D) 700/9 Explanation: Let Veena's weight = 1 kg Sana's weight = 2 kg Sneha's weight = 1.4 kg Rina's weight = 1.8 kg Now,according to the given data in the question, 1.8x100 = 1.4 x = 1.4 × 1001.8 = 7009 = 77 79.
Q: 45 men working 9 hours per day dig 40 m deep. How many extra men should be put to dig to a depth of 56 m working 7 hours per day ? 2006 05b5cc6dae4d2b4197774e8c8
5b5cc6dae4d2b4197774e8c8- 136true
- 261false
- 348false
- 454false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "36"
Explanation :
Answer: A) 36 Explanation: (45 x 9)/40 = (M x 7)/56 => M = 81 => 81 – 45 = 36
Q: The average age of 7 boys is increased by 1 year when one of tem whose age is replaced by a girl. What is the age of the girl ? 2006 05b5cc6cae4d2b4197774e086
5b5cc6cae4d2b4197774e086- 133 yrsfalse
- 227 yrsfalse
- 321 yrsfalse
- 429 yrstrue
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "29 yrs"
Explanation :
Answer: D) 29 yrs Explanation: Let the avg age of 7 boys be 'p' yearsLet the age of the girl be 'q' yearsFrom given data,The age of 7 boys = 7p yearsNow the new average = (p + 1) when 22 yrs is replaced by qNow the age of all 7 will become = 7(p + 1) yrsHence, 7p - 22 + q = 7(p + 1) yrs7p - 22 + q = 7p + 7q = 22 + 7 = 29 Therefore, the age of girl = q = 29 years.
Q: In following number series only one number is wrong. Find out that wrong or odd number in the series? 6, 78, 858, 7722, 54055, 270270 2004 05b5cc6bce4d2b4197774d8bb
5b5cc6bce4d2b4197774d8bb- 1270270false
- 254055true
- 37722false
- 4858false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "54055"
Explanation :
Answer: B) 54055 Explanation: Here the given series follows a pattern that, multiplying the number with odd numbers in decreasing order starting with 13. That is, 6 × 13 = 78 65 × 11 = 858 858 × 9 = 7722 7722 × 7 = 54054 54054 × 5 = 270270 Hence, the wrong number is 54055
Q: A motorboat takes half time to cover a certain distance downstream than upstream. What is the ratio between rate of current and rate of boat in still water? 2003 05b5cc6afe4d2b4197774d1e7
5b5cc6afe4d2b4197774d1e7- 11 : 3true
- 23 : 2false
- 32 : 3false
- 43 : 1false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "1 : 3"
Explanation :
Answer: A) 1 : 3 Explanation: Let the speed of the boat in still water is 'w' Speed of the current is 'c' Let the distance between two places is 'd' According to the question, motorboat takes half time to cover a certain distance downstream than upstream. dw+c = 12dw-c => 2w - 2c = w + c => w = 3c => c : w = 1 : 3 Hence, the ratio between rate of current(c) and rate of boat in still water(w) = 1 : 3