Correct Answer - Option 1 : 20
Cost Price = ₹ 500
Initial SP = ₹ (100 + x)/100 of 500 = ₹ (500 + 5x)
New CP = ₹ (100 – x + 10)% of 500 = ₹ 5(110 – x) = ₹ (550 – 5x)
New SP = 130% of (550 – 5x)
⇒ New SP = 715 – 6.5x
⇒ (500 + 5x) – (715 – 6.5x)= 15
⇒ - 215 + 11.5x = 15
⇒ 11.5x = 230
⇒ x = 230/11.5
⇒ x = 20