Need assistance with this question which is incorrect. Is there a specific formula for this and what is the MAGI and phase outs for these in 2020? Thanks.

Under what circumstances is it advantageous for a taxpayer to make a nondeductible contribution to a traditional IRA rather than a contribution to a Roth IRA? Tax Payer Status a. Married filing joint b. Single/Head of household $ Maximum AGI limit Starting phase out limit 196,000 $ 206,000 124,000 $ 139,000 $