Correct Answer - Option 4 : 20%
Given:
She lost 20% when she sold it at 3/5 of actual selling price.
Formula Used:
Gain/Profit = SP – CP,
Percent gain/Profit = (SP – CP)/CP × 100,
Where,
SP is selling price,
CP is cost price
Calculation:
Let the cost price be Rs. 100
When she sold at 3/5 of actual selling price he lost 20% on CP
⇒ 3/5 × SP = 80% × 100
⇒ 3/5 × SP = 80/100 × 100
⇒ 3/5 × SP = 80
⇒ SP = (80 × 5)/3
⇒ SP = 400/3
Actual selling price is 400/3
Now she sold at 90% of a actual selling price.
⇒ 90/100 × 400/3
⇒ 120
Now gain = SP – CP
⇒ Gain = 120 – 100
⇒ Gain = 20
Gain % = P/CP × 100
⇒ Gain % = 20/100 × 100
⇒ Gain % = 20%
∴ Total gain percent is 20%.