Maths profit and loss ?

7.
₹1 = 100 paise

Cost of 2 dozen pencils
= 72 × (12 × 2) paise
= 1728 paise
= ₹17.28

Selling price of 2 dozen pencils
= ₹7.20 × 2
= ₹14.40 < ₹17.28

Since the selling price is lower than the cost price, he lost.

Loss percent
= (Loss/Cost) × 100%
= [(17.28 - 14.40)/17.28] × 100%
= (16 2/3)%
≈ 16.67%

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8.
Cost of 1 orange
= 50/3 paise

Selling price of 1 orange
= 60/2 paise
= 30 paise

Gain percentage
= (Gain/Cost) × 100%
= {[30 - (50/3)] / (50/3)} × 100%
= [(40/3) / (50/3)] × 100%
= (40/50) × 100%
= 80%