Question
There are thirty balls in my cupboard in complete
disarray. Ten are black, ten are red and ten are brown, but I cannot distinguish the colors in the dark. How many balls should I take from the cupboard so that there is at least one pair of the same color?Solution
Total number of balls = 30 There are 3 colored balls present in 30 balls. When we take out 3 balls, there is a possibility that all three balls may be of different colors. But when we take out 4 balls (at least), then two balls of one color will come out. Hence, there will be a pair of the same color present in 4 balls.
What is the operational speed target for the Golden Quadrilateral trains?
What type of bridges are commonly used in mountain railways?
The first electric train ran in India with the inauguration of services between Bombay VT and Kurla Harbour on 3 February:
Which railway track in India uses the rack-and-pinion system for steep sections?
The total of 42 separate railway systems, including ______ owned by the former Indian princely states, existed at the time of independence spanning a t...
_______ private companies incorporated in Britain constructed and managed the early trunk lines in India.
Which system is most suitable for bridges and large-scale structures?
On the recommendation of _____ in 1978, a number of electrification works were taken up in Indian Railways.
For the Darjeeling Himalayan Railway, protective measures are enshrined in the Railway Act of 1989, which replaced the:
Calcutta (now Kolkata) had been linked by rail in _____ to Siliguri, at the foothills of the Himalayas.
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