Question
A bag contains red, blue, and green balls in the ratio
of 2:4:5. If two balls are randomly selected from the bag, the probability that both are blue is 1/8 . Determine the total number of balls in the bag.Solution
Let the number of red, blue and green balls in the bag are 2x, 4x and 5x respectively. Total number of balls in the bag = 2x + 4x + 5x = 11x So according to question: 4xC2/11xC2 = 1/8 4x (4x – 1)/ 11x (11x – 1) = 1/8 (16x – 4)/ (121x – 11) = 1/8 128x – 32 = 121x – 11 7x = 21, x = 3 So the total number of balls in the bag = 33
A person who spends 55% of his salary saves the remainder. His salary goes up by 15%, but his savings stay the same, and he now spends Rs. 3,300 more. D...
A car covers the first 40 km of a journey at 60 km/h and the next 60 km at 90 km/h. What is the average speed for the entire journey?
Two pipes A and B can fill a tank in 12 hours and 16 hours, respectively. A third pipe C can empty the tank in 24 hours. If all three pipes are opened t...
Two pipes A and B can fill a tank in 15 hours and 20 hours, respectively. If both pipes are opened together and then pipe A is closed after 5 hours, how...
The set of all bijective functions from a finite set A to itself forms:
Find the value of 25 mod 6
How many Kg of rice costing rupees 19 per kg must be mixed with 26 Kg of rice costing Rs.25 per Kg, so that there may be a gain of 17.5% by selling the ...
Determine the area of an equilateral triangular field having perimeter of 42m.
Find the surface area of the smallest cube that can perfectly fit a sphere of volume 288Ï€ cm3 inside it. Â
A pipe can fill a tank in 6 hours, while another pipe can empty it in 8 hours. If both pipes are opened together, how long will it take to fill the tank?
