फसल उत्पादन एवं प्रबंध | Class 8 विज्ञान | 7 PM Class by Amba Ma'am | L2 | Hindi Medium

12 PM Special Class | Class 11 - STRUCTURE OF ATOM || BOHR MODEL By Yakshu Ma'am

Thirty children were asked about the number of hours they watched TV programmes in the previous week. The results were found as follows: 1 6 2 3 5 12 5 8 4 8 10 3 4 12 2 8 15 1 17 6 3 2 8 5 9 6 8 7 14 12 (i) Make a grouped frequency distribution table for this data, taking class width 5 and one of the class intervals as 5 - 10. (ii) How many children watched television for 15 or more hours a week?

The marks obtained by 40 students of class IX in an examination are given below: 18, 8, 12, 6, 8, 16, 12, 5, 23, 2, 16, 23, 2, 10, 20, 12, 9, 7, 6, 5, 3, 5, 13, 21, 13, 15, 20, 24, 1, 7, 21, 16, 13, 18, 23, 7, 3, 18, 17, 16 Present the data in the form of a frequency distribution using the same class size, one such class being 15-20 (where 20 is not included)

The marks obtained by 40 students of class VIII in an examination are given below: 18,8,12,0,8,16,12,5,23,2,16,23,2,10,20,12,9,7,6,5,3,5, 13,21,13,15,20,24,1,7,21,16,13,18,23,7,3,18,17,16 Present the data in the form of a frequency distribution using the same class size, one such class being 15-20 (where 20 is not included).

Consider the marks, out of 100, obtained by 51 students of a class in a test, given in Table 14.9. M a r k s"N u m b e r o f S t u d e n t s"0-10 5 10-20 10 20-30 4 30-40 6 40-50 7 50-60 3 60-70 2 70-80 2 80-90 3 90-100 9Tot a l 51 Draw a freque

KMnO_4 is prepared from the mineral pyrolusite, MnO_2 (deep purple colour). It acts as an oxidising agent in the neutral, alkaline as well as acidic medium in acidic medium it is used in volumetric analysis for estimation of Fe^(2+) , Cr_2O_4^(2-) salts etc. The titrations are carried out in presence of H_2SO_4 . However, before using it as a titrant, it is first standardised with standard oxalic acid solution or Mohr's salt solution . In one of the experiments on titration 26.8g of dry pure sodium oxalate (Mw=123gmol^-1) was dissolved in 1L of distilled water and then 100 mL of 2MH_2SO_4 were added. The solution was cooled. Now to this solution 0.1MKMnO_4 solution was added till a very faint pink colour persisted. Q. Mohr's salt, FeSO_4(NH_4)_2SO_46H_2O , is preffered over FeSO_4.7H_2O for standardisation of KMnO_4 solution because.

KMnO_4 is prepared from the mineral pyrolusite, MnO_2 (deep purple colour). It acts as an oxidising agent in the neutral, alkaline as well as acidic medium in acidic medium it is used in volumetric analysis for estimation of Fe^(2+) , Cr_2O_4^(2-) salts etc. The titrations are carried out in presence of H_2SO_4 . However, before using it as a titrant, it is first standardised with standard oxalic acid solution or Mohr's salt solution . In one of the experiments on titration 26.8g of dry pure sodium oxalate (Mw=123gmol^-1) was dissolved in 1L of distilled water and then 100 mL of 2MH_2SO_4 were added. The solution was cooled. Now to this solution 0.1MKMnO_4 solution was added till a very faint pink colour persisted. Q. If 0.1MK_2Cr_2O_7 solution were used in place of 0.1 MKMnO_4 solution used would be

Ratio of the fares of First ,Second and Third class catogory of a train , between two stations is 10:7:2 and the ratio of passenger travelling in these category is 4:9:17 respectively .If the fare is increased by 1/4 in First class , 1/8 in second class and decreased by 10% i Third Class and the ratio of number of passenger in the category remains same .If the total amount received of Rs. 60590 , then find the total amount received from thrid class category .