मानव नेत्र तथा रंगबिरंगा संसार | CLASS 10 - विज्ञान | 7 AM Class by Ruchi Katiyaar Ma'am | L8

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

The average weight of a certain number of students in a class is 68.5 kg. If 4 new students having weights 72.2 kg, 70.8kg, 70.3kg and 66.7 kg join the class, then the average weight of all the students increases by 300 g. The number of students in the class, initially is: किसी कक्षा में छात्रों की एक निश्चित संख्या का औसत वज़न 68.5 किलो ग्राम है | यदि 4 नए छात्र कक्षा में आ जाते हैं, जिनका वज़न क्रमशः 72.2 किलो ग्राम, 70.8 किलो ग्राम, 70.3 किलो ग्राम तथा 66.7 किलो ग्राम है, तो सभी छात्रों का औसत वज़न 300 ग्राम से बढ़ जाता है | आरंभ में कक्षामें छात्रों की संख्या कितनी थी ?

A train M leaves station X at 5 a.m and reaches station Y at 9 a.m. Another train N leaves station Y at 7 a.m. and reaches station X at 10.30 a.m. At what time do the two trains cross each other? 7. 36 adotmdot b. 7. 56 adotmdot c. 8. 36 adotmdot d. 8. 56 adotmdot

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?

Tabulate , the given data by taking Class intervals : 1-10 , 11- 20 , 21- 30 , 31- 40 Data : 9 , 10 , 8 , 6 , 7 , 4 , 3 , 2, 16 , 28 , 22 , 36 , 24 , 18 , 27 , 35 , 19 , 29 , 23 , 34.

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 .

Pipes A, B and C can fill a tank in 30h, 40 h and 60 h respectively. Pipes A, B and C are opened at 7 a.m., 8 a.m., and 10 a.m., respectively on the same day. When will the tank be full? पाइप A, B और C किसी टंकी को क्रमशः 30, 40 और 60 घंटों में भर सकते हैं | पाइप A, B और C को एक ही दिन क्रमशः सुबह 7, 8 और 10 बजे चालू किया जाता है | टंकी किस समय भर जाएगी ?