20
30
40
5
7^6n- 6^6n, where n is an integer >0, is divisible by
72 % of the students of a certain class took Biology and 44% took Mathematics. If each students took at least one of Biology or Mathematics and 40 students took both of these subjects, the total number of the student in the class is
794.99 ÷ 15.001 + 768.025 ÷ 12.012 - 1273.025 ÷ 18.999 = ?
7X2 is a three-digit number in which X is a missing digit. If the number is divisible by 6, the missing digit is -
8 litres are drawn from a cask filled with wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in cask to that of the total solution is 16 : 81. How much wine did the cask hold originally?
8 litres are drawn from a cask full of wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in cask to that of the water is 16 : 65. How much wine the cask hold originally?
8 men can do a work in 12 days. After 6 days of work, 4 more men were engaged to finish the work. In how many days would the remaining work be completed?
80% of a number added to 80 gives the result as the number itself, then the number is :
80% of a smaller number is 4 less than 40% of a larger number. The larger number is 85 greater than the smaller one. The sum of these two number is
84 Maths books, 90 Physics books, 120 Chemistry books have to be stacked topicwise. How many books will be there in each stack so that each stack will have the same height too ?