Solution:

Number of 50 paisa coins = 100

Number of 1 rupee coins = 50

Number of 2 rupee coins = 20

Number of 5 rupee coins = 10

Total number of coins = 100+50+20+10 = 180

(i) Probability of getting a 50 paisa coin,

= 100/180

= 5/9

(ii)Probability that coin will not be Rs.5 coin,

= (100+50+20)/180

= 170/180

= 17/18