Question
The average age of 12 boys in the group is 9 years. If 2
more boys join the group, the average is increased by 1 year. What is the average age (in years) of the two new boys in the group?Solution
Average age of 12 boys in a group=9 years Total Age =12Ă—9=108 years 3 more boys join the group so the total boys =12+2=14 boys And increased average by 1=9+1=10 years So total age of 14 boys =14Ă—10 =140 years total age of new 2 boys =140-108=32 years average age of new 2boys = 32/2=16 years Â
- The cost of tea increased by 25%, so Meena reduced her consumption by 20%. Calculate the percentage change in her expenditure on tea.
A man spends 21% and 12% of his monthly salary on rent and transportation, respectively. Out of the remaining money, he spends 26% on food and 41% on en...
- A refrigerator depreciates in value by 18% in the first year and then 12% in the next year. If its price after 2 years is Rs. 25,872, what was its initial ...
Heena decided to save 15% of her salary as fixed deposit. Later, she changed her mind and saved Rs 4800 which was 80% of what she had decided earlier. ...
In an election two candidates participated. 10% voters did not vote. 11(1/9)% votes declared invalid and the winner got 75% of the valid votes. If he wo...
In a bio gas plant the population of yeast bacteria increases at a rate of 19% per annum but there is an additional annual increase of 1% in population ...
A factory produces three types of products: A, B, and C. The ratio of the number of units produced for A, B, and C is initially 3:4:5. After a revision ...
Out of 700 people in a club, 15% speak Russian and the rest speak Ukrainian. If out of non-Russian speakers, 60% are males and out of Russian speakers 8...
A company produces three types of products: A, B, and C. The total number of products produced in a month is 18,000. The production distribution is as f...
By selling 36 m of jute, a shopkeeper gains an amount equal to the selling price of 12 m of jute. Find the gain percentage.