Base currency is traditionaly the stronger currency and also the one which is actually bought or sold when we deal in pairs

For e.g. if we BUY GBPUSD then we are Buying GBP and Selling USD , Here GBP is the Base currency and USD is the counter currency

first currency

Rupee

Monetary base- which is the sum of bank reserves and currency in circulation. The formulas of MB ismonetary base = reserves + currency (MB =R+C)

You can do 2 things Divide the currency you've got now by the base rate of the other currency Times the base rate of one currency by how many in the other. Or just put in google the two currencies