Question
In how ways can the selection be made so that a
particular member is always included? There are 5 members in a delegation which is to be sent abroad. The total no. of members is 11.ÂSolution
As the person is always included, therefore, ∴ C_1 × 10C_4  =  1 × (10 × 9 × 8 × 7)/(4 × 3 × 2)  = 210
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...
The average wage of a group of 25 labourers is Rs. 470. If 4 persons receiving average wage of Rs. 350 leave the group and 2 persons receiving average w...
Four numbers are arranged in ascending order. When the first two numbers are increased by the number equal to their position, and the last two numbers i...
In a cricket match the captain of one of a team scored 24 runs more than the average runs scored by the remaining 7 batsmen of that team who batted in t...
The average age of three children is 16 years. If their ages are in the ratio 1:3:4. Find the age of the youngest child.
The average score of a class of boys and girls in examination is X. The ratio of boys and girls in the class is 4:3. If the average score of the boys (X...
The average age of 13 girls is 40 years. If the age of one more girl is added the average decreases by half a year. What is the age of new girl?
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...
Average run scored by a batsman in 16 innings is 40. In next 6 innings, he scored runs with an average of ‘x’ so that his overall average increases ...
The ratio of apples to oranges in a basket is 2:1. The average weight of oranges is (w − 3) grams and the average weight of all fruits is (w + 3) gram...
