Percentage - Study Mode

[#181] Raman's salary is increased by 5% this year. If his present salary is Rs. 1806, the last year's salary was :
Correct Answer

(A) Rs. 1720

Explanation

Solution: Required last year salary = $$frac{1806}{100 + 5}$$ xa0 × 100 = Rs. 1720

[#182] If 80% of A = 50% of B and B = x% of A, then the value of x is :
Correct Answer

(C) 160

Explanation

Solution: 80% of A = 50% of B ⇒ $$frac{80}{100}$$A = $$frac{50}{100},$$B ⇒ 8A = 5B ⇒ A = $$frac{5}{8}$$B Put value of A in given equation, B = x% of A ⇒ B = $$frac{x}{100}$$ × $$frac{5}{8},$$B ⇒ x = $$frac{100 × 8}{5}$$ ⇒ x = 160

[#183] The percentage of metals in a mine of lead ore is 60%. Now the percentage of silver is $$frac{3}{4}$$% of metals and the rest is lead. If the mass of ore extracted from this mine is 8000 kg, the mass (in kg.) of lead is :
Correct Answer

(B) 4764

Explanation

Solution: Mass of lead ore = 8000 kg ⇒ Mass of metal in lead ore = 60% of 8000 = 4800 kg ⇒ Mass of silver in metal = $$frac{3}{4}$$% of 4800 = 36 kg ⇒ Mass of lead in ore = 4800 - 36 = 4764 kg

[#184] If 120 is 20% of a number, then 120% of that number will be :
Correct Answer

(D) 720

Explanation

Solution: Let the number = x According to the question, x × $$frac{20}{100}$$ = 120 x = 600 Required answer = 600 × $$frac{120}{100}$$ = 720 Alternate 20% represents → 120 1% → $$frac{120}{20}$$ So, 120% = $$frac{120}{20}$$ × 120 = 720

[#185] 498 is 17% less than a number then the number is :
Correct Answer

(C) 600

Explanation

Solution: Let the number = x According to the question, ⇒ x - $$frac{17x}{100}$$ = 498 ⇒ 100x - 17x = 49800 ⇒ 83x = 49800 ⇒ x = $$frac{49800}{83}$$ = 600