Question Detail

Teacher took exam for English, average for the entire class was 80 marks. If we say that 10% of the students scored 95 marks and 20% scored 90 marks then calcualte average marks of the remaining students of the class.

  • 60
  • 70
  • 75
  • 80

Answer: Option C

Explanation:

Lets assume that total number of students in class is 100 and required average be x.
Then from the given statement we can calculate :
(10 * 95) + (20 * 90) + (70 * x) = (100 * 80)

=> 70x = 8000 - (950 + 1800) = 5250

=> x = 75.

Similar Questions :

1. 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}

2. What will be the fraction of 20%

  • 1/4
  • 1/5
  • 1/10
  • None of above

Answer: Option B

Explanation:

It will 20*1/100 = 1/5

3. If number x is 10% less than another number y and y is 10% more than 125, then find out the value of x

  • 123.55
  • 123.65
  • 123.75
  • 123.85

Answer: Option C

4. Due to an increase in 30% in the price of eggs, 3 eggs less are available for Rs. 7.80. Find the present rate of eggs per dozen.

  • Rs. 9.36
  • Rs. 10.36
  • Rs. 11.36
  • Rs. 12.36

Answer: Option A

Explanation:

Let the original price per egg be Rs x
Then increased price will be,
\begin{aligned}
\left(\frac{130}{100}x\right) \\
=> \frac{7.80}{x}-\frac{7.80}{\frac{130}{100}x} = 3\\
=> \frac{7.80}{x}-\frac{780}{130x} = 3 \\
=> 390x = 234 \\
=> x = 0.6 \\

\text{Actual price was Rs 0.6} \\
\text{Present price per dozen will be} \\
Rs.\left(12*\frac{130}{100}*0.6 \right) \\
= Rs. 9.36
\end{aligned}

5. 2 is what percent of 50

  • 2%
  • 4%
  • 6%
  • 8%

Answer: Option B

Explanation:

2/50 * 100 = 1/25 * 100 = 4 %

Read more from - Percentage Questions Answers