IIT JEE प्रश्न और उत्तर का अभ्यास करें
8प्र: A secret can be told to only 3 persons in 3 minutes. Each person in turn tells 3 other persons in the next 3 minutes and the processes continues accordingly. In 30 minutes how many persons can be told this secret in this way ? 2549 05b5cc741e4d2b4197774f99a
5b5cc741e4d2b4197774f99a- 188572true
- 277854false
- 399584false
- 455654false
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उत्तर : 1. "88572"
व्याख्या :
Answer: A) 88572 Explanation: Given a secret is told to 3 persons in 3 minutes.And if the process continues with each person saying 3 other persons,In 30 minutes => the rocess for 10 times because each person time is 3 minutes.Required number of persons = 3 + 32 + 33 + .... + 39 + 310 Now it forms a geometric progression, Sum to n terms is S = arn - 1r - 1 Here a = 3, r = 3 => 59048 x 3 /2 = 88572.
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 ? 2547 05b5cc73ae4d2b4197774f8dd
5b5cc73ae4d2b4197774f8dd- 149.6%true
- 250.4%false
- 333.67%false
- 466.66%false
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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: When Ionic bonds are formed metallic atoms tend to 2545 05b5cc697e4d2b4197774c5a5
5b5cc697e4d2b4197774c5a5- 1share electronsfalse
- 2gain electronsfalse
- 3lose electronstrue
- 4None of abovefalse
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उत्तर : 3. "lose electrons"
व्याख्या :
Answer: C) lose electrons Explanation: Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. Hence, when Ionic bonds are formed metallic atoms tend to lose electrons and become positive ions
प्र: Which of the following is Not an Operating System? 2544 05b5cc6afe4d2b4197774d1b0
5b5cc6afe4d2b4197774d1b0- 1UNIXfalse
- 2Windows NTfalse
- 3C++true
- 4DOSfalse
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उत्तर : 3. "C++"
व्याख्या :
Answer: C) C++ Explanation: C++ is not an Operating System. An Operating System is a collection of system programs that manages all the other programs application programs in a computer as well as the allocation and use of hardware resources such as the CPU, Memory and the Hard Disk Drive. It acts as an interface between the hardware and the user level program. It controls and facilitates the overall operation of a computer. Here UNIX : UNIX is a popular multi-user, multitasking operating system (OS) developed at Bell Labs. Windows NT : Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. DOS : DOS is Disk Operating System. The term DOS can refer to any operating system. C++ : C++ is a programming language and computing platform. Hence, C++ is not an Operating System.
प्र: A Conical tent was erected by the army at a base camp with height 3 m and base diameter 10 m. If every person requires 3.92 cu.m air, then how many persons can be seated in that tent approximately? 2543 05b5cc6bfe4d2b4197774da97
5b5cc6bfe4d2b4197774da97- 120true
- 219false
- 317false
- 422false
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उत्तर : 1. "20"
व्याख्या :
Answer: A) 20 Explanation: Given height of the conical tent = 3 m Diameter = 10 => Radius = D/2 = 10/2 = 5 m Now, as the tent is in the conical form Volume of the conical tent = πr2h3 => (22 x 5 x 5 x 3) / (7 x 3) = 22 x 25/7 = 78.54 cu.m Given each person requires 3.92 cu.m of air => Number of persons can be seated in the tent = 78.54/3.92 = 20.03 =~ 20
प्र: The Mudumalai National Park is located in which state ? 2541 25b5cc6e0e4d2b4197774eb4d
5b5cc6e0e4d2b4197774eb4d- 1Chattisgarhfalse
- 2Haryanafalse
- 3Tamil Nadutrue
- 4Karnatakafalse
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उत्तर : 3. "Tamil Nadu"
व्याख्या :
Answer: C) Tamil Nadu Explanation: The Mudumalai National Park (MNP) is located about 150 kilometres north-west of Coimbatore city in Tamil Nadu. The protected area is home to several endangered and vulnerable species including Indian elephant, Bengal tiger, gaur and Indian leopard. There are at least 266 species of birds in the sanctuary, including critically endangered Indian white-rumped vulture and long-billed vulture.
प्र: A box contains 90 screws each of 100 gms and 100 bolts each of 150 gms. If the entire box weighs 35.5 kg, then the weight of the empty box is ? 2541 05b5cc731e4d2b4197774f7e2
5b5cc731e4d2b4197774f7e2- 110.5 kgsfalse
- 212 kgsfalse
- 39.6 kgsfalse
- 411.5 kgstrue
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उत्तर : 4. "11.5 kgs"
व्याख्या :
Answer: D) 11.5 kgs Explanation: Screws weight = 90x100 = 9000gmsbolts weight = 100 x 150 = 15000gmsweight = screws + bolts => 24000 gms =>24 kgGiven entire box weight = 35.5kgempty box = entire box weight - weight => 35.5kg - 24kg => 11.5kgso the empty box is 11.5kg.
प्र: A can do a piece of work in 10 days, B in 15 days. They work together for 5 days, the rest of the work is finished by C in two more days. If they get Rs. 3000 as wages for the whole work, what are the daily wages of A, B and C respectively (in Rs): 2541 05b5cc7d0e4d2b419777511d6
5b5cc7d0e4d2b419777511d6- 1200, 250, 300false
- 2300, 200, 250true
- 3200, 300, 400false
- 4None of thesefalse
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उत्तर : 2. "300, 200, 250"
व्याख्या :
Answer: B) 300, 200, 250 Explanation: A's 5 days work = 50% B's 5 days work = 33.33% C's 2 days work = 16.66% [100- (50+33.33)] Ratio of contribution of work of A, B and C = 50 : 3313 : 1623 = 3 : 2 : 1 A's total share = Rs. 1500 B's total share = Rs. 1000 C's total share = Rs. 500 A's one day's earning = Rs.300 B's one day's earning = Rs.200 C's one day's earning = Rs.250

