1. How much is 80% of 40 is greater than 4/5 of 25?

**Answer: **12

**Explanation:**
80% of 40 = 40 * (80/100) and 4/5 fo 25 = 25 * 4/5

[40* (80/100) - 25*(4/5) ] = [3200/100 - 100/5]

= 32 - 20 = 12

2. After decreasing 24% in the cost price of an article,its costs Rs.912. Find the actual cost of an article?

**Answer: **1200

**Explanation:**
CP* (76/100) = 912 => CP = 912 * 100/76

CP= 12 * 100

=> CP = 1200

cost price of article = Rs. 1200

3. Ravi's salary was reduced by 25%.Percentage increase to be effected to bring the salary to the original level is

**Answer: **33 1/3 %

**Explanation:**
Method: 1

Let's assume Ravi salary = 100

It get reduced by 25% => Salary = 75

75(1 + P/100) = 100

1+ P/100 = 4/3

P = 100/3 = 33 1/3%.

Method: 2

You can use directly formula i.e

[(R*100)/(100-R)]% Where 'R' is decresed %

so put 25 at place of 'R'

=> [(25 * 100)/(100 - 25)]% => [(25 *100)/75]%

=>100/3% = 33 1/3%

4. Fresh fruit contains 68% water and dry fruit contains 20% water. How much dry fruit can be obtained from 100 kg

**Answer: **40

**Explanation:**
1. Given fresh fruit has 68% water,

=> Remaining 32% will be fruit content.

2. Given Dry fruit has 20% water

=> Remaining 80% is fruit content.

Here assume weight of dry fruit = x kg.

"fruit content in both the fresh fruit and dry fruit is the same"

Fruit % in fresh-fruit = fruit% in dry-fruit

so (32/100) * 100 = (80/100 )* x

=> x = 40 kg.

5. Ram donated 4% of his income to a charity and deposited 10% of the rest in a Bank. if now he has Rs 8640 left with him, then his income is

**Answer: **Rs. 10000

**Explanation:**
Let Ram's Income = Rs. 100.

Donation to charity = Rs. 4

Amount deposited in bank = (96 * l0)/100 = Rs. 9.6

Savings = (100 - 13.6) = Rs. 86.4

so Rs. 86.4 = 100

=> Rs. 8640 = (100/86.4) * 8640 = Rs. 10000

6. In a certain company, 20% of the men and 40% of the women attended the annual company picnic. If 35% of all the employees are man, what percent of all the employees went to the picnic?

**Answer: **33%

**Explanation:**
Lets assume that total 100 employees are in company.

out of that 35 are man and remaining 65 are women.

20% of man 35 = 20*35/100

40% of women = 40*65/100

total employees = 7+26 = 33 out of 100

=> 33 %

7. A student multiplied a number by 3/5 instead of 5/3. What is the percentage error in the calculation?

**Answer: **64%

**Explanation:**
Let the number be x.

Then, error = x*5/3 - x*3/5 = x * 16/15

So Error% = ( x*16/15 * 3/5x * 100)% = 64%.

8. If A's height is 40% less than that of B, how much percent B's height is more than that of A?

**Answer: **66.66%

**Explanation:**
Excess of B's height over A's = [(40/(100 - 40)] x 100%

= 66.66%

9. In a certain college, 20% of the boys and 40% of the girls attended the annual college outing. If 35% of all the students are boys, what percent of all the employees went to the outing?

**Answer: **33%

**Explanation:**
Lets assume total students =100

so in that 35 students are boys and remaining 65 will be girl.

20% of boys = (35)*20/100 = 7

40% of girls = (65)*40/100 = 26

Totally (26+7)=33 employee went to outing.

So 33 is 33% in 100

=> 33% employees went for outing.

10. If the price of petrol increases by 25%, by how much must a user cut down his consumption so that his expenditure on petrol remains constant?

**Answer: **20%

**Explanation:**
Let the petrol 1 unit initial price be rs 100.

25% increase on rs 100= rs 125

since expenditure to remain constant 125*x= 100*1

x=.80 unit

So, consumer reduces =.20 unit i.e 20%