Answer
(a) See image.
(b)
$\$400$ tax for $\$14000$ income
$\$1900$ tax for $\$26000$ income
(c) Tax Assessed T(I) = $$0, if I ∈ (0, 10000]$$
$$10, if I ∈ (0.1I-1000, 20000]$$
$$15, if I ∈ (0.15I-2000, +\infty)$$
See image below.
Work Step by Step
(a) Rate of Income Tax R(I) = $$0, if I ∈ (0, 10000]$$
$$10, if I ∈ (10000, 20000]$$
$$15, if I ∈ (20000, +\infty)$$
(b) In the case of 14000 (dollars) income:
the first 10000 (dollars) tax assessed will be (0%) 0 (dollars)
for the next 4000 (dollars) tax assessed will be (10%) 400 dollars
so for 14000 (dollars) income tax assessed will be 400 (dollars).
In the case of 26000 (dollars) income:
the first 10000 (dollars) will be taxed (0%) 0 (dollars)
the next 10000 (dollars) will be assessed (10%) 1000 (dollars) tax
and the remaining 6000 (dollars) will be assessed (15%) 900 (dollars) tax
So, for 26000 (dollars) income tax assessed will be 1900 (dollars).
(c) Tax Assessed T(I) = $$0, if I ∈ (0, 10000]$$
$$10, if I ∈ (0.1I-1000, 20000]$$
$$15, if I ∈ (0.15I-2000, +\infty)$$
