There are four different letters and four different letter boxes, in how many methods these letters can be dropped in the boxes,
if all the four letters in a single box are not allowed:
Total no. of methods without any condition = 4*4*4*4 = 256
No of methods of taking all the four letters in a box = 4
Hence required methods with given condition = 256-4 = 252
Murugan sold a book at a loss of 40%. If the selling price had been increased by Rs.200, there would have been a gain of 10%. What was the cost price of the book?
Let cost price be Rs ‘x’ Then (110% of x) – (60 % of x) = 200 (110x/100) - (60x/10) = 200 110x – 60x = 20000 X = 400 So cost price of the book = Rs.400
Kiran rides her scooter 14km at an average speed of 16 km/hr and again travels 16km at an average speed of 14 km/hr. What is her average speed for the entire trip approximately?
Total distance travelled =14+16=30Km
Time taken to travel 14 km at an average speed of 16 km/hr =14/16=7/8 Hr
Time taken to travel 16 km at an average speed of 14 km/hr =16/14=8/7 hr
Total time taken =7/8+8/7 Average speed =Total distance travelled /Total time taken =30/(7/8+8/7) =30/(113/56)
=30*56/113=1680/113
=14.86 km/hr
3 of our users Amar, Akbar and Anthony attempt to solve a puzzle together, their chances of solving the puzzle is 2/7, 3/5, 4/9.
What is the probability that the puzzle will be solved by them?
Probability that Amar would not be able to solve the puzzle = 1 - 2/7 = 5/7
Probability that Akbar would not be able to solve the puzzle = 1 - 3/5 = 2/5
Probability that Anthony would not be able to solve the puzzle = 1 - 4/9 = 5/9
Probability that puzzle is not solved = (5/7)*(2/5)*(5/9) = 10/63
Hence Probability that puzzle is solved = 1- 10/63 = 53/63
Option 4)
A string is 148 cm long. It is cut into 3 pieces. The longest piece is 4 times as long as the middle-sized
piece & the shortest piece is 77 cm shorter than the longest piece. Find the length of the shortest piece (in cm).
A is 20 years older than B who is five times as old as C. The total of the ages of A, B and C is 174 years. What is the value when the square of age of B is multiplied to the sum of ages of A and C ?