Question
Seven books out of which 4 are novels and rest are comics
have to be arranged on a shelf. Find the number of ways of arrangement in which all four novels are not placed together.Solution
Total number of ways of arrangement = 7! = 5040 ways
If we consider 4 novels as one book, number of ways of arrangement among themselves = 4! = 24 ways
Number of ways of arrangement of remaining 4 items = 4! = 24 ways
Therefore, required number of ways = 5040 – (24 × 24) = 4464 ways
A student multiplied a number by 8/5 instead of 5/8. What is the percentage error in the calculation?
A certain sum becomes Rs 13650 at 15% p.a. simple interest after 2 years. What will be the amount (in RS) of the same sum after 1 year at the same rate ...
If A's salary is 60% more than B's salary, then by what percentage is B's salary less than that of A?
P spends 27% of his salary on transportation, 30% on food, 18% on children’s education and 16% on medical. He deposits the remaining amount of Rs....
The only expenses of Arun are on grocery, rent and fun expenses. Arun spent Rs. 2,750 on fun, amount spent by him on rent is Rs. 9,000 more than that on...
In 2020, Maran earned Rs. 16,500, spending 40% of it and saving the remainder. The following year, his earnings increased by 20%, and his expenditures a...
J's salary is 35% less than V's salary, then how much percent more or less is J's salary compared to G's salary, given that G's s...
In a village election between two candidates, the winner secured 54% of the total votes cast and won by a majority of 4000 votes. How many votes did the...
- A car’s value depreciates by 10% in the first year and 20% in the second year. If its value after 2 years is Rs. 28,800, find the original value of the c...
An original figure is first enhanced by 25% and then reduced by 10%. What is the final overall percentage change?
