First S.P = ₦230.00

% profit = 15%

% profit = $\frac{S.P-C.P}{C.P}$ x 100%

⇒ 15% = $\frac{230-C.P}{C.P}$ x 100%

⇒ $\frac{15}{100}=\frac{230-C.P}{C.P}$

⇒15C.P = 100 (230 - C.P)

⇒15C.P = 23000 - 100C.P

⇒15C.P + 100C.P = 23000

⇒115C.P = 23000

⇒ C.P = $\frac{23000}{115}$ = ₦200.00

Second S.P = ₦180.00

Since C.P is greater than S.P, therefore it's a loss

% loss = $\frac{C.P-S.P}{C.P}$ x 100%

⇒ $\frac{200-180}{200}$ x 100%

⇒ $\frac{20}{200}$ x 100%

⇒ $\frac{1}{10}$ x 100% = 10%

∴ It's a loss of 10%