Answer:
John's standard deduction for 2019 is $12,200 (plus $2,950) = $15,150
Step-by-step explanation:
Standard deduction is a way reducing taxable income by neglecting a portion of an individual's income.
In John's case, in 2019, he is Over 65 and blind which gives him $1,300 more deduction. He is also unmarried as his wife is dead so that gives him another $1,650 deduction more.
In total, he has the the standard deduction of $12,200 + his conditional deduction of ($1,300 + $1,650)
= $15,150
Cheers.