Question
A bowl contains 9 blue balls, 7 white, and 5 black
balls. If 2 balls are drawn in one go, then the probability of exactly one ball being white is:Solution
In total, we have 9+7+5=21 balls. We have drawn 2 balls; we can draw them in 21C2 ways = 21! ÷ (19! ×2!) = 210 ways. In those two balls, we need one to be a white ball, so we can include that in 7C1 ways = 7 ways. The remaining ball may be any color ball but not white, so we select other balls in 14C1 ways= 14 ways. Probability= (7×14)/210 =7/15.
In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option...
- Parts of the following sentence have been given as options. Select the option that contains an error.
She sings more better than anyone in the cho... The following sentence has been split into four segments. Identify the segment that contains a grammatical error.
The concert has started when he...
Out of the statements given below, one statement may be grammatically and contextually correct. Choose the correct statement as your answer. If all the...
- Read the following sentence to find out if there is any grammatical error in it. The error, if any, will be in one part of the sentence. The number of this...
- The sentence is divided into four parts marked as (A), (B), (C), and (D). One of the parts may contain a grammatical error. Identify the part that has the ...
A sentence has been divided into four parts, one of which may contain an error. Identify that fragment and mark it as your answer. Mark (E) if the sent...
Read the given sentence to find out whether there will be error in any of the two parts, mark the parts in which there will be error as answer from the ...
While issues like high blood pressure, (1)/diabetes and smoking are widely discussed as (2)/public health concerns, a very few know that poor air qualit...
- Read each sentence to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Mark the part with the...
Relevant for Exams:
