Pablo deposited 57 into a savings account for which interest is compounded quarterly according to the rule 72 what interest rate will cause his money to double is approximately 44 years
R= annual rate 72/0.25r=44.4 44*4 is the number of compounding periods 72.4/r =176,,288/r=176 so 176r = 288
r = 288/176
r = 1.636 percent or 0.01636
Let's check
1.01636^44 = just over 2