Question
A college group of 50 students has an average age of 23
years. 10 new students are added and the average age decreases to 21. What is the average age of the new students?Solution
Initial sum = 50 × 23 = 1150 years
New total = 60
New average = 21
New total sum = 60 × 21 = 1260 years
Sum of new = 1260 - 1150 = 110 years
Average = 110 ÷ 10 = 11 years
In a city, the number of persons travelling by bike is 50% the number of persons travelling by metro. The number of persons travelling on foot is 80% th...
In an election two candidates participated. 10% voters did not vote. 11(1/9) % votes declared invalid and the winner got 50% of the valid votes. If he w...
Initially, a person spends 80% of his salary and saves the remaining 20%. After receiving a 10% salary increase, his savings remain unchanged, and he sp...
- If the price of a milk packet is reduced by 20%, by what percentage should a family increase its consumption of milk to ensure that their total expenditure...
A invested a certain amount in Debt and Equity mutual funds in the ratio of 3: 7 respectively. At the end of one year, he earned a total dividend of 30%...
- The population of a city increases by 18% every year. If the population after 2 years will be 41,472, what is the present population?
In an exam, Riya scored 40% and fell short of the pass mark by 20 marks, whereas Mehul scored 50% and exceeded the passing mark by 10 marks. What are th...
There are 108 girls in a class who can read. If 40% of students in the class are girls, out of which 75% can read, then find the number of students in t...
The income of a person is Rs.13000 and his expenditure is Rs.8000. In the next year his income and expenditure is increased by 10% and 20% respectively....
A girl spent 20% of her monthly income on clothing. Of the remaining, she spent on travel and food in the ratio of 3:2. If the difference of the income ...
