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

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. The ratio 5:20 expressed as percent equals to

50 %
125 %
25 %
None of above

Answer: Option C

Explanation:

Actually it means 5 is what percent of 20, which can be calculated as,
(5/20)*100 = 5 * 5 = 25

3. 88% of 370 + 24% of 210 - x = 118

Answer: Option D

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

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. What is 15 percent of 34

5.10
4.10
3.10
2.10

Answer: Option A

Explanation:

It will be 15% of 34
= (15/100) * 34 = 5.10