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Who decides the prices of different vegetables in the vegetable market?
In a vegetable market, neither a single trader nor the government directly fixes the retail prices of daily produce. Prices emerge organically through the continuous interaction between buyers and sellers. The collective demand of consumers wanting to purchase vegetables interacts with the total marRead more
In a vegetable market, neither a single trader nor the government directly fixes the retail prices of daily produce. Prices emerge organically through the continuous interaction between buyers and sellers. The collective demand of consumers wanting to purchase vegetables interacts with the total market supply available each day, thereby establishing a prevailing market price based on underlying demand and supply pressures.
For more NCERT Solutions of Class 9 Social Science Chapter 9 The Price Puzzle What Drives the Market Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/social-science/
See lessA man of mass 60 kg rides a scooter of mass 100 kg. He accelerates the scooter to a velocity v. The next day, his son with a mass of 40 kg joins him as a passenger. If the scooter reaches the same speed on both days in the same time interval, what is the ratio of the fuel of the tank used on the two days? Assume that the energy transfer to the scooter happens entirely due to fuel, and no other losses occur due to air resistance and friction.
Since fuel energy converts entirely into kinetic energy, fuel used is proportional to total kinetic energy. On the first day, combined mass is 60 kg plus 100 kg, which equals 160 kg. On the second day, combined mass is 160 kg plus 40 kg, equaling 200 kg. At the same final speed, the ratio of kineticRead more
Since fuel energy converts entirely into kinetic energy, fuel used is proportional to total kinetic energy. On the first day, combined mass is 60 kg plus 100 kg, which equals 160 kg. On the second day, combined mass is 160 kg plus 40 kg, equaling 200 kg. At the same final speed, the ratio of kinetic energies and fuel consumed is 160 to 200, simplifying to 4 is to 5.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-7/
See lessWrite the sample space and calculate the probability based on the given information. (i) Two dice are rolled. What is the probability that the sum is a prime number greater than 5? (ii) A bag contains 4 red, 3 green, and 2 blue balls. Two balls are drawn without replacement. What is the probability that both are of different colours? (iii) Three coins are tossed. What is the probability that the first coin shows heads and exactly two heads occur in total? (iv) A four-digit number is formed using the digits 1, 2, 3, and 4 with no repetition. What is the probability that the number is even? (v) A student takes a multiple-choice test with 3 questions, each having 4 options (A, B, C, D), with only one correct answer. What is the probability that the student guesses and gets exactly 2 answers correct?
(i) Total pairs = 36. Primes greater than 5 are 7 and 11: {(1,6), (2,5), (3,4), (4,3), (5,2), (6,1), (5,6), (6,5)} (8 pairs). P = 8/36 = 2/9. (ii) Total pairs = (9 x 8) / 2 = 36. Same color pairs = 4x3/2 (red) + 3x2/2 (green) + 2x1/2 (blue) = 6 + 3 + 1 = 10. Different colors = 36 - 10 = 26. P = 26/3Read more
(i) Total pairs = 36. Primes greater than 5 are 7 and 11: {(1,6), (2,5), (3,4), (4,3), (5,2), (6,1), (5,6), (6,5)} (8 pairs). P = 8/36 = 2/9.
(ii) Total pairs = (9 x 8) / 2 = 36. Same color pairs = 4×3/2 (red) + 3×2/2 (green) + 2×1/2 (blue) = 6 + 3 + 1 = 10. Different colors = 36 – 10 = 26. P = 26/36 = 13/18.
(iii) S has 8 outcomes. Favourable are {HHT, HTH}. P = 2/8 = 1/4.
(iv) Total numbers = 4x3x2x1 = 24. Even ends in 2 or 4: 2 x 6 = 12. P = 12/24 = 1/2.
(v) Each question P(C) = 1/4, P(W) = 3/4. Exactly 2 correct: CCW, CWC, WCC. P = 3 x (1/4)² x (3/4) = 9/64.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 7 The Mathematics of Maybe: Introduction to Probability Question Answer (2026-27)
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See lessAn atom has 79 protons and a mass number of 197. Calculate (i) the number of neutrons and (ii) the number of electrons.
The mass number represents the sum of protons and neutrons within the nucleus. Subtracting 79 protons from the mass number 197 gives 118 neutrons. Since an atom is electrically neutral, the total count of negatively charged electrons must equal the total count of positively charged protons. ThereforRead more
The mass number represents the sum of protons and neutrons within the nucleus. Subtracting 79 protons from the mass number 197 gives 118 neutrons. Since an atom is electrically neutral, the total count of negatively charged electrons must equal the total count of positively charged protons. Therefore, this neutral atom contains 79 electrons orbiting its central nucleus.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
See lessAman was discussing the structure of atom with his classmates. During the discussion, he learnt that an element X has a mass number of 35 and contains 18 neutrons. Based on this information, answer the following questions: (i) How many electrons and protons does element X have? (ii) What is its atomic number? (iii) Identify the element X. (iv) Write its electronic configuration. (v) How many valence electrons does it have? (vi) What will be the mass number if two neutrons are added to its nucleus? (vii) What will be the relation of X with the new atom?
Subtracting 18 neutrons from mass number 35 gives 17 protons and 17 electrons. Its atomic number is 17, identifying it as chlorine Cl. The electronic configuration is 2, 8, 7, having seven valence electrons. Adding two neutrons increases its mass number from 35 to 37. Since both atoms have identicalRead more
Subtracting 18 neutrons from mass number 35 gives 17 protons and 17 electrons. Its atomic number is 17, identifying it as chlorine Cl. The electronic configuration is 2, 8, 7, having seven valence electrons. Adding two neutrons increases its mass number from 35 to 37. Since both atoms have identical atomic numbers but different mass numbers, the new atom is an isotope of chlorine.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
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