Percentage - Study Mode
[#316] If 20% of (A + B) = 50% of B, then value of $$frac{2A - B}{2A + B}$$ xa0 is :
Correct Answer
(A) $$frac{1}{2}$$
Explanation
Solution: $$frac{20}{100}$$ (A + B) = $$frac{50}{100}$$ (B) 2A + 2B = 5B 2A = 3B A = $$frac{3}{2}$$ put value of A in given equation $$frac{2A - B}{2A + B}$$ = $$frac{3B - B}{3B + B}$$ = $$frac{2B}{4B}$$ = $$frac{1}{2}$$
[#317] Ticket for all but 100 seats in a 10000 seat stadium were sold. Of the ticket sold, 20% were sold at half price and the remaining tickets were sold at the full price of Rs. 20. The total revenue from the ticket sales, (in Rs.) was :
Correct Answer
(B) 178200
Explanation
Solution: Total seats = 10000 Ticket sold = (10000 - 100) = 9900 According to the question, Total revenue = 9900 × $$frac{20}{100}$$ × 10 + 9900 × $$frac{80}{100}$$ × 20 = 9900 × 2 + 9900 × 16 = 9900 (2 + 16) = Rs. 178200
[#318] The average of marks obtained by 100 candidates in a certain examination is 30. If the average marks of passed candidates is 35 and that of the failed candidates is 10, what is the number of candidates who passed the examinations ?
Correct Answer
(C) 80
Explanation
Solution: By mixture and allegation method. 4 : 1 = 5 units 5 units = 100 1 unit = 20 Pass candidate : = 4 units = 4 × 20 = 80
[#319] If 90% of A = 30% of B and B = 2x% of A, then the value of x is :
Correct Answer
(D) 150
Explanation
Solution: 90% of A = 30% of B 90A = 30B ⇒ B = 3A ..... (i) B = $$frac{2x}{100}$$ × A 3A = $$frac{2x}{100}$$ × A ⇒ x = 150
[#320] 18% of which number is equal to 12% of 75 ?
Correct Answer
(A) 50
Explanation
Solution: Let the number = x According to the question, ⇒ x × $$frac{18}{100}$$ = $$frac{12}{100}$$ × 75 ⇒ 18x = 12 × 75 ⇒ x = $$frac{12 × 75}{18}$$ ⇒ x = 50 Hence, required number = 50