Solution:
a) Deposits= Bank Reserves/ (Reserve-deposit ratio)
= $250 / 0.25 = $1,000
Money supply =Currency held by the public+ Deposits
= $200 + $1,000 = $1,200
b) The savings and currency of the country are equivalent in this case. Its worth should be equal to x and deposits should have money supply less currency.
r = reserves/total deposits
0.25 = x / ($600 - x)
x = 150 - 0.25x
1.25 x =150
x =120
So, the currency held by public is $120
Bank reserves are $120
c) As the money supply is $1,400 and the public holds $500 in currency, bank deposits must equal $900
If bank reserves are $90,
the desired reserve/deposit ratio equals $90/$900 = 0.1