Question

A purse contains $10$ five hundred rupee note, $20$ hundred rupee notes, $30$ fifty rupee notes and $40$ ten rupee notes. If it is likely that one of the notes will fall out when the purse turns upside. What is the probability that the note will not be a five hundred rupee note?

• A. $\frac{7}{10}$
• B. $\frac{9}{10}$
• C. $\frac{3}{10}$
• D. None of these

Answer 1

Answer: (B)

$\frac{9}{10}$

Total number of notes in purse $=$$10$+$20$+$30$+$40$$=$ $100$

Therefore, total number of elementary events $=$ $100$

The note will not be a $500$ rupee note $:$

There are $20$+$30$+$40$ $=$ $90$ notes other than $500$ rupee note

Therefore, favourable number of elementary events $=$ $90$

Hence, $P$(falling out of note other than $500$ note) $:$

$\frac{90}{100}=\frac{9}{10}$