Which pair of ratios is proportional?

a.
6/21 and 2/42

b.
25/100 and 50/150

c.
18/24 and 6/12

d.
7/14 and 20/40

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?