Mr. and Mrs. Pratt failed to apply for an extension of time to le their 2014 Form

Question:

Mr. and Mrs. Pratt failed to apply for an extension of time to ﬁle their 2014 Form 1040 and didn’t mail the return to the IRS until May 29, 2015. Assuming the Pratts had no excuse for ﬁling a delinquent return, compute their late-ﬁling and late-payment penalty if:
a. The return showed a $19,758 balance of tax due.
b. The return showed a $7,098 refund due.