Question Detail

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

1. If sales tax is reduced from 5% to 4%, then what difference it will make if you purchase an item of Rs. 1000

Answer: Option A

Explanation:

Clue: Answer will be 5% of 1000 - 4% of 1000

2. A student multiplied a number by 3/5 instead of 5/3. What is the percentage error.

Answer: Option A

Explanation:

Let the number be x,
then,
\begin{aligned}
\frac{5}{3} - \frac{3}{5} = \frac{16}{15}x
\end{aligned}

Error% = \begin{aligned}
(\frac{16}{15}x * \frac{3}{5} * 100)% = 64%
\end{aligned}

3. 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.

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.

4. Raman's salary was decreased by 50% and subsequently increased by 50%. How much percent does he loss.

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%

5. Evaluate 28% of 450 + 45% of 280

Answer: Option C

Explanation:

= (28/100) * 450 + (45/100) * 280
= 126 + 126 = 252