1) let x be the number of Rs 500
so, 200 - x is the number of Rs 200 (because the number of prizes must sum up to 200 to be distributed amongst the 200 persons)
Rs 500*(number of Rs 500) + Rs 200*(number of Rs 200) = Rs 50000
(Rs 500)(x) + (Rs 200)(200-x) = Rs 50000
500x + 40000 - 200x = 50000 (just distributed Rs 200)
500x - 200x = 50000 - 40000 (40000 was subtracted from both sides of the equation)
300x = 10000
x = 33.3333 <--- number of Rs 500
200 - x = 166.666667 <--- number of Rs 200
the answers must be whole numbers... but if you will round it off to the nearest unit digit, there will only be a total of Rs 49900. so, it is not possible for 200 Rs 50000 to exist consisting only of either Rs 500 or Rs 200.
2) let x be the worth of Bryan's property
(Son's share) + (Daughter's share) + (Wife's share) = (total worth of Bryan's property)
(1/5)(x) + (1/5)(x) + Rs 288000 = x
(2/5)(x) + Rs 288000 = x
Rs 288000 = x - (2/5)(x)
Rs 288000 = (3/5)(x) (multiplying both sides of the equation by 5/3)
Rs 480000 = x
so, Bryan's property is worth Rs 480000