The cost price of a table is Rs. 800. Rohit marked it up by Rs. x above its cost price and gave r% discount on the marked price. If he earned 25% profit, then find the value of
x.
I. A sum of Rs. 10000 becomes Rs. 14400 after 2 years at r% compound interest.
II. r = 20%
III. 800r + xr = 25000

ATQ, CP = 800 MP = 800 + x Profit = 25% So, SP = 800 × 125/100 = 1000 Therefore, 1000 = (800 + x) × (100 - r)/100 ---- (1) From I A sum of Rs. 10000 becomes Rs. 14400 after 2 years at r% compound interest. 14400/10000 = (1 + r/100)² 36/25 = (1 + r/100)² 6/5 = 1 + r/100 r = 20% Now put r = 20 in equation (1): 1000 = (800 + x) × 80/100 800 + x = 1250 x = 450 So, Statement I is sufficient. From II r = 20% Now put r = 20 in equation (1): 1000 = (800 + x) × 80/100 800 + x = 1250 x = 450 So, Statement II is sufficient. From III 800r + xr = 25000 r(800 + x) = 25000 From equation (1), 1000 = (800 + x)(100 - r)/100 => 100000 = (800 + x)(100 - r) Also, r(800 + x) = 25000 So, 100(800 + x) - 25000 = 100000 100(800 + x) = 125000 800 + x = 1250 x = 450 So, Statement III is sufficient. Hence, all three statements are sufficient.