Question
A vessel contains 50 liters of a solution with 40% acid.
10 liters of this solution are removed and replaced with a solution containing 70% acid. The process is repeated once more. What is the final concentration of acid in the solution?Solution
Initial acid = 40% of 50 liters = 20 liters. After first replacement: Acid remaining = 20 - 4 = 16 liters. Acid added = 7 liters. Total acid = 16 + 7 = 23 liters. After second replacement: Acid remaining = 23 - 4.6 = 18.4 liters. Acid added = 7 liters. Total acid = 18.4 + 7 = 25.4 liters. Final concentration = 25.4/50 × 100 = 50.8%
Evaluate: 360 ÷ [ {18 − (6×2)} × 5 ] + 72 − 33
(43)² - (28)² + (32)² = ?% of 2500
Evaluate:
√729 + √49 - √16 + 1/√64
What will come in place of (?) in the given expression.
12.5 + 7.75 - 3.6 = ?62 of 8 - 320 ÷ 4 = ?3 + 200
2(1/3) + 2(5/6) – 1(1/2) = ? – 6(1/6)
What will come in the place of question mark (?) in the given expression?
30% of 520 + 16% of 1500 = ? + 244
60% of 120 – ?% of 64 = 20% of 200
35% of 840 + 162 = ? – 25% × 300
20% of 240 + 18% of 200 = ?
