Question 1153423
Simple Interest formula:

{{{FV  =P (1 + rY) }}}

where 

{{{FV }}} = final payout 
{{{P=10000}}}
{{{r=5}}}%={{{0.05}}}
{{{Y=3}}} (number of years)

bank {{{a}}}:

{{{FV  =  10000(1 +0.05*3)}}}
{{{FV  =10000(1 +0.15)}}}
{{{FV  =11500}}}


bank {{{b}}}:

{{{FV  =  10000(1 +0.055*2.5)}}}
{{{FV  =10000(1 +0.1375)}}}
{{{FV  =11375}}}

the difference between the two banks final payout figure: ${{{11500-11375=125}}}

answer:
b. ${{{125}}}