Question
A sample contains equal numbers of two isotopes X and Y,
each with half-lives of 10 days and 20 days respectively. What is the ratio of activities Aβ : Aᡧ after 20 days?Solution
There are only 220 students living in hostel. If 20 students left hostel, then overall expenditure of mess is reduced by Rs. 800 weekly but per student ...
The average height of each student in a class of 36 students is 169 cm. If 4 new students joined the class, then the average height of the each student ...
The average cost of 3 chairs is Rs. 10000. The average cost decrease by 22% when one more chair is included. What is the cost price of the 4th
- The average value of the property of Rina, Tanya and Kavya is Rs. 90 lacs. The value of the property of Rina is Rs. 30 lacs less than the value of the prop...
A set contains ten numbers. The average of the first six numbers is (x - 4), and the average of the last three numbers is (x + 2). The average of the en...
A batsman had an average of 39 runs in 35 innings. In his next 5 innings, he scored 100, 85, 90, 80, and 60. What is his updated average?
The ages of 4 members of a family are in the year 2011 are βXβ,βX+6β,βX+12β and βX+18β. After some years Oldest among them was dead then...
- The average of 36 numbers is 75. If every number is multiplied by 9, what will be the average of the resulting numbers?
The average marks of a class of 40 students were 75. When the marks of 5 students were removed, the average marks of the remaining students became 72. W...
The average age of a group of 80 students is 14 years. If 3 students whose ages are 16 years, 22 years, and _____ years are replaced by 3 new students w...
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