IIT JEE Practice Question and Answer
8Q: The average age of 80 boys in a class is 15. The average age of group of 15 boys in the class is 16 and the average of another 25 boys in the class is 14. What is the average age of the remaining boys in the class ? 1698 05b5cc736e4d2b4197774f883
5b5cc736e4d2b4197774f883- 112.24 yrsfalse
- 213.25 yrsfalse
- 316 yrsfalse
- 415.25 yrstrue
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "15.25 yrs"
Explanation :
Answer: D) 15.25 yrs Explanation: Total ages of 80 boys = 15 x 80 = 1200 yrs.Total age of 16 boys = 15 x 16 = 240 yrsTotal age of 25 boys = 14 x 25 = 350 yrs.Average age of remaining boys = 1200 - (240+350) / 80 - (25+15) = 610/41 = 15.25 yrs.
Q: ____________has became the second city in the country, and the first in south India, to have a full-fledged Metro rail. 1698 05b5cc6d4e4d2b4197774e5b6
5b5cc6d4e4d2b4197774e5b6- 1Bangaloretrue
- 2Chennaifalse
- 3Keralafalse
- 4Hyderabadfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "Bangalore"
Explanation :
Answer: A) Bangalore Explanation: Bengaluru has became the second city in the country, and the first in south India, to have a full-fledged Metro rail in operation following the opening of a final 12-km section of the 42-km first phase of the Metro project. The first phase, comprising an 18-km east-west line and a 24-km north-south line, built at a cost of Rs 13,845 crore, was dedicated to the nation by President Pranab Mukherjee at an event in Bengaluru.
Q: The perimeter of a square is equal to twice the perimeter of a rectangle of length 8cm and breadth 7cm. What is the circumference of a semicircle whose diameter is equal to the side of the square ? 1697 05b5cc736e4d2b4197774f841
5b5cc736e4d2b4197774f841- 155.12 cmfalse
- 222.54 cmfalse
- 342.51 cmfalse
- 438.57 cmtrue
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "38.57 cm"
Explanation :
Answer: D) 38.57 cm Explanation: We know that perimeter of rectangle = 2(l+b) = 2(8+7)= 30cmGiven perimeter of square is twice the perimeter of rectangle = 2(30) = 60cmTherefore, side of the square is = 1/4 x 60 = 15cmCircumference of the required semicircle = πr + 2r = 227× 152 + 2×152 = 23.57 + 15 = 38.57cm.
Q: The difference between circumference and semidiameter of a circle is 37 cm. What is the diameter of the circle ? 1697 05b5cc6c6e4d2b4197774de27
5b5cc6c6e4d2b4197774de27- 118 cmfalse
- 212 cmfalse
- 316 cmfalse
- 414 cmtrue
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "14 cm"
Explanation :
Answer: D) 14 cm Explanation: circumference of a circle = 2πr => 2 × 22/7 × r – r = 37 => 37/7 × r = 37 => r = 7 cm. Diameter D = 2r = 7×2 = 14 cm.
Q: What type of lens is a magnifying glass? 1697 05b5cc69de4d2b4197774c8e6
5b5cc69de4d2b4197774c8e6- 1Divergingfalse
- 2Sphericalfalse
- 3Convergingtrue
- 4Achromaticfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "Converging"
Explanation :
Answer: C) Converging Explanation: A magnifying glass is a convex lens that is used to produce a magnified image of an object. It is also called a hand lens in laboratory contexts.
Q: Which of the following is not a Fundamental Right? 1697 05b5cc622e4d2b4197774b807
5b5cc622e4d2b4197774b807- 1Right To Freedom Of Speech And Expressionfalse
- 2Right To Employmenttrue
- 3Right To Equalityfalse
- 4Right To Educationfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "Right To Employment"
Explanation :
Answer: B) Right To Employment Explanation: Fundamental Rights are the basic rights of the common people and inalienable rights of the people who enjoy it under the charter of rights of Constitution of India. The six fundamental rights recognised by the Indian constitution are:: the right to equality, right to freedom, right against exploitation, right to freedom of religion, cultural and educational rights, right to constitutional remedies.
Q: Solid Carbon dioxide is known as 1697 05b5cc6ace4d2b4197774d0a6
5b5cc6ace4d2b4197774d0a6- 1Wet Icefalse
- 2Dry Icetrue
- 3Solid Icefalse
- 4Nonefalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "Dry Ice"
Explanation :
Answer: B) Dry Ice Explanation: Dry ice or Cardice is the solid form of Carbon dioxide. 1. It has an advantage of lower temperature than the water ice and doesn't leave any residue. 2. The reason why it is called as Dry ice is because unlike the normal ice, it won't melt into liquid form. It directly evaporates into the air as gas. That is Solid to gas form passing through liquid state is a phenomenon called as Sublimation. 3. The primary use of dry ice is as cooling agent.
Q: The least number of complete years in which a sum of money put out at 20% C.I. will be more than doubled is ? 1697 05b5cc6e2e4d2b4197774ec25
5b5cc6e2e4d2b4197774ec25- 13 yearsfalse
- 24 yearstrue
- 32.5 yearsfalse
- 42 yearsfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "4 years"
Explanation :
Answer: B) 4 years Explanation: P1+20100n > 2P Now, (6/5 x 6/5 x 6/5 x 6/5) > 2. So, n = 4 years.

