Question
How many terms are there in the geometric progression 4,
20, 100...... 62500?Solution
First term (a) = 4  common differences (r) = 20/ 4=5 T = 62500 Tn = arn-1 62500=4× (5)n-1 625×25 = (5)n-1 56 = (5)n-1 n-1=6 n=7 Hence the number of terms (n) = 7
If average of first 12 numbers is (n – 23) and the sum of remaining number is 925. Find the value of ‘n’, if the average of 22 numbers is ‘n’....
Average marks scored by Vineet in five subjects are 65. The average marks scored by him (excluding his highest and lowest marks) are 50 and lowest marks...
In a team of 24 players, the average age is 27 years. Later, 6 new players join the team and the average age becomes 24 years. What is the average age o...
A mixture contains oil and water in the ratio 7:5. When 70% of this mixture is replaced with 153 litres of water, the ratio becomes 8: 13. Than, what wi...
The average weight of 8 students in a class is (x + 15). If the average of the first four students is 30 kg and the average of the last four students is...
The average weight of 7 boxes P, Q, R, S, T, U and V is 72kg. Another box A is added to group and the average now becomes 70kg. If another box C whose ...
A number is such that when it is multiplied by 3, it gives another number which is as much above from 240 as the original number (itself) is below 240. ...
In a company team of 18 members, the average age is 29 years. When 6 more members join, the average age falls to 26. What is the average age of the new ...
The average of 7 consecutive odd numbers is 39. What is the smallest of these numbers?
The average number of books on history, polity and geography in a library is 144, and the average number of books on history and geography is 140. If th...
Relevant for Exams:
