Four Square Services Corporation estimates that its 2021 taxable income will be $1,000,000. Thus, it incurs a $210,000 liability. For the following independent cases, compute Four Squares minimum quarterly estimated tax payments that will avoid an underpayment penalty. a. For 2020, taxable income was $800,000, and tax liability was $168,000.

b. For 2019, taxable income was $2 million, and tax liability was $680,000. For 2020, taxable income was $100,000, and tax liability was $21,000.