A piggy bank contaons

Number 50 p coins in the piggy bank = 100
Number of Re. 1 coins in the piggy bank = 50
Number of Rs. 2 coins in the piggy bank = 20
Number of Rs. 5 coins in the piggy bank = 10
∴ Total number of coins in the piggy bank  = 100 + 50 + 20 -10 = 180
∴ Number of all possible outcomes = 180

1. Number of favourable outcomes to the event that the coin will be a 50 p coin  = 100
   ∴ Probability that the coin will be a 50 p coin 
    {tex}\frac{Number\;of\;favourable\;outcomes\;to\;the\;event\;that\;the\;coin\;will\;be\;a\;50\;p\;coin}{\;Number\;of\;all\;possible\;outcomes}{/tex}  {tex}\frac{100}{180}=\frac59{/tex}
2. Number of favourable outcomes to the event that the coin will not be a Rs. 5 coin
   = 100 + 50 + 20 = 170
   ∴ Probability that the coin will not be Rs. 5 coin
   {tex}\frac{Total \ no.\;of\;favourable\;outcomes}{Total\;number\;of\;possible\;outcomes}{/tex}  {tex}\frac{170}{180}=\frac{17}{18}{/tex}