Question Detail
If x% of y is 100 and y% of z is 200, then find the relation between x and z.
- z = x
- 2z = x
- z = 2x
- None of above
Answer: Option C
Explanation:
It is , y% of z = 2(x% of y)
=> yz/100 = 2xy/100
=> z = 2x
1. Rahul's Mathematics test had 75 problems, 10 arithmetic, 30 algebra, 35 geometry problems. Although he answered 70% of arithmetic, 40% of arithmetic and 60% of geometry problems correctly, still he got less than 60% problems right. How many more questions he would have to answer more to get passed
- 5
- 6
- 7
- 8
Answer: Option A
Explanation:
Number of questions attempted correctly = (70% of 10 + 40% of 30 + 60% of 35)
= 7 + 12 + 21 = 40.
Questions to be answered correctly for 60% = 60% of total quations
= 60 % of 75 = 45.
He would have to answer 45 - 40 = 5
2. Raman's salary was decreased by 50% and subsequently increased by 50%. How much percent does he loss.
- 75
- 65
- 45
- 25
Answer: Option D
Explanation:
Let the origianl salary = Rs. 100
It will be 150% of (50% of 100)
= (150/100) * (50/100) * 100 = 75
So New salary is 75, It means his loss is 25%
3. A batsman scored 120 runs which included 3 boundaries and 8 sixes. What percent of his total score did he make by running between the wickets.
- 40%
- 50%
- 60%
- 70%
Answer: Option B
Explanation:
Number of runs made by running = 110 - (3 x 4 + 8 x 6)
= 120 - (60)
= 60
Now, we need to calculate 60 is what percent of 120.
=> 60/120 * 100 = 50 %
4. Total number of boys and girls in a school is 150. If the number of boys is x, then girls become x% of the total number of students. The number of boys is
- 50
- 60
- 70
- 80
Answer: Option B
Explanation:
Clearly,
x% of 150 = 150 - x [as x is number of boys]
\begin{aligned}
=> x + \frac{x}{100} * 150 = 150 \\
=> \frac{5}{2}x = 150 \\
=> x = 60 \\
\end{aligned}
5. In an election between two candidates, 75 % of the voters cast their votes, out of which 2% of the votes were declared invalid. A candidate got 9261 votes which were 75% of the total valid votes. Find the total number of votes.
- 16800
- 15800
- 16700
- 15700
Answer: Option A
Explanation:
Let the total number of votes enrolled are x.
Number of votes cast = 75% of x
Valid votes = 98% of 75% of x
Now, as 9261 is the 75% of valid casted votes so,
75% of 98% of 75% of x = 9261 [imporant]
\begin{align}
=> \frac{75 \times 98 \times 75 \times x}{100 \times 100 \times 100} = 9261 \\
=> x = 16800
\end{align}