Question
The average number of books on history, polity and
geography in a library is 120, and the average number of books on history and geography is 130. If the number books on geography is 20% less than the number of books on polity, then what is the number of books on history in the library?Solution
Let the number of books on History, Polity and Geography be x, y and z respectively. Given, (x + y + z)/3 = 120 Or, x + y + z = 360 ….. (1) And, (x + z)/2 = 130 Or, x + z = 260 ….. (2) From equation 1 and 2 Number of books on polity = y = 100 Number of books on geography = 0.8 × 100 = 80 Therefore, number of books on history = 360 – (100 + 80) = 180
An agricultural revolution is when farming changes a lot in a short time. These revolutions have led to transformative outcomes in the country's agricul...
The creation of utility by the way of marketing is called as
Which of the following is considered as an essential step in the exchange of gases during respiration and photosynthesis?
Which crop does not contribute to food grain production?
In which of the following technique, DNA from different sources are isolated and digested with restriction endonuclease?
Which layer of the atmosphere has lowest average temperature?
Which one the following Country has largest area under drip irrigation in the world?
Which of the following is a measure to promote the export of organic products under India's Agricultural Export Policy?
Which one of the following primitive type of corn has less economic importance?
In a breeding experiment involving quantitative traits, a breeder calculated the phenotypic variance (VP) as 40 and genotypic variance (VG) as 30. Based...
