(a) Let the cost of the car to the dealer be x.
Sales of car to a man with 15% profit : (115% of x = 1.15 x\)
Sale of the car to the woman by the man at 5% loss : (95% of 1.15x = N120,175.00)
$0.95\times 1.15x=N120,175.00$
$1.0925x=N120,175.00$
$x=\frac{120,175.00}{1.0925}$
$x=N110,000$
The original cost of the car to the dealer = N110,000.00.
(b) Circumference of a circle = $2\pi r$
Distance covered by the wheel = 1.05 km
Radius of the wheel = 18cm
Circumference of the wheel = $2\times \frac{22}{7}\times 18$
= $113.14cm$
Note : 1.05 km = 105,000 cm
Number of revolution = $\frac{105,000}{113.14}$
= $928.05revs$
$\approxeq 928revs$