Question 1

The price of ghee is increased by 32%. Therefore, a family reduces its consumption, so that the increment in price of ghee is only 10%. If consumption of ghee is 10 kg before the increment, then What is the consumption now?

Accepted Answer

Let price of ghee before increment = ₹ N Consumption = 10 kg Then, expenditure on ghee = ₹ 10N After increment, Expenditure on ghee = 110% of 10N = 11N Price of ghee = 132% of N = (N x 132)/100 = 33N/25 per kg ∴ Now consumption = (11N x 25) / 33N kg = 81/3 kg

Question 2

The expenses on wheat, meat and vegetable of a family are in the ratio 12 : 17 : 3. The prices of these articles are increased by 20%, 30% and 50% respectively, The total expenses of the family on these articles are increased by?

Accepted Answer

Let expenses on wheat be 12N. Expenses on meat = 17N. Expenses on vegetables = 3N. ∴ Total expenses = 32N. Increased expenses = ₹ (120% of 12N) + (130% of 17N) + (150% of 3N)] = ₹ [(120/100) x 12N] + [(130/100) x 17N] + [(150/100) x 3N] = ₹ [72N/5 + 221N/10 + 9N/2] = ₹ (144N + 221N + 45N)/10 = ₹ 410N/10 = ₹ 41 ∴ Total increase percentage = (9N/32N) x 100 % = 225/8 % = 281/8%

Question 3

In 1998, ratio of the numbers of students taking examinations in x and z states are respectively 3 : 5 : 6. Next year, the numbers of students are increased by 20%, 10% and 20% respectively. If ratio of the numbers of students in states x and z is 1…

Accepted Answer

In 1998 Let number of students in x = 3k Number of students in y = 5k and Number of students in z = 6k Next year, number of students in x = 3k + 20% of 3k = 18k/5 Number of students in y = 5k + 10% of 5k = 11k/2 Number of students in z = 6k + 20% of 6k = 36k/5 According to the question, (18k/5) / (36k/5) = 1/2 Thus, data is insufficient.

Question 4

The tank-full of petrol in Arun's motor-cycle lasts for 10 days. If he starts using 25% more everyday, how many days will the tank-full of petrol last?

Accepted Answer

Let us assume that Arun uses N units of petrol everyday. so the amount of of petrol in the tank when it is full will be 10N. If he starts using 25% more petrol everyday. then the units of petrol he now use everyday will be N(1 + 25/100) = 1.25N So, the number of days his petrol will now last will be equal to (amount of petrol in tank) / (number of units used everyday) = (10N) / (1.25N) = 10 / 1.25 = 8 days

Question 5

In a examination out of 480 students, 85% of the girls and 70% of the boys passed. How many boys appeared in the examination, if total pass percentage was 75%?

Accepted Answer

Total number of students = 480 percentage of total students passed = 75% of total student = (75 x 480)/100 = 360 students Now, using the condition from the question. Let the number of boys be N Then, 70% of N + 85% of (480 - N) = 360 ⇒ [(70 x N)/100] + [85 x (480 - N)]/100 = 360 ⇒ 70N - 85N + 40800 = 36000 ⇒ 40800 - 36000 = 85N - 70N ⇒ 4800 = 15N ⇒ N = 4800/15 = 320 ∴ There are 320 boys who appeared for the examination,

Question 6

In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got, was :

Accepted Answer

Total number of votes = 7500 Given that 20% of Percentage votes were invalid => Valid votes = 80% Total valid votes = 7500*(80/100) 1st candidate got 55% of the total valid votes. Hence the 2nd candidate should have got 45% of the total valid votes => Valid votes that 2nd candidate got = total valid votes x (45/100) 7500*(80/100)*(45/100) = 2700

Question 7

Fresh fruit contains 68% water and dry fruit contains 20% water. How much dry fruit can be obtained from 100 kg of fresh fruits ?

Accepted Answer

The fruit content in both the fresh fruit and dry fruit is the same. Given, fresh fruit has 68% water.so remaining 32% is fruit content. weight of fresh fruits is 100kg Dry fruit has 20% water.so remaining 80% is fruit content.let weight if dry fruit be y kg. Fruit % in freshfruit = Fruit% in dryfruit Therefore, (32/100) x 100 = (80/100 ) x y we get, y = 40 kg.

Question 8

If 20% of a = b, then b% of 20 is the same as :

Accepted Answer

20% of a = b => (20/100) * a = b b% of 20 =(b/100) x 20 = [(20a/100) / 100] x 20= 4a/100 = 4% of a.

Question 9

The value of a machine depreciates at the rate of 10% every year. It was purchased 3 years ago. If its present value is Rs. 8748, its purchase price was :

Accepted Answer

Purchase price = R s . 8748 1 - 10 100 3 = Rs. [8748 * (10/9) * (10/9 )* (10/9)] = Rs.12000

Question 10

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

Accepted Answer

Let the number be x. Then, ideally he should have multiplied by x by 5/3. Hence Correct result was x * (5/3)= 5x/3. By mistake he multiplied x by 3/5 . Hence the result with error = 3x/5 Then, error = (5x/3 - 3x/5) = 16x/15 Error % = (error/True vaue) * 100 = [(16/15) * x/(5/3) * x] * 100 = 64 %

Question 11

A student has to obtain 33% of the total marks to pass. He got 125 marks and failed by 40 marks. The maximum marks are :

Accepted Answer

Given that the student got 125 marks and still he failed by 40 marks => The minimum pass mark = 125 + 40 = 165 Given that minimum pass mark = 33% of the total mark => total mark =33/100 =165 => total mark = 16500/33 = 500

Question 12

if the price of a book is first decreased by 25% and then increased by 20%, then the net change in the price will be :

Accepted Answer

Let the original price be Rs. 100. New final price = 120 % of (75 % of Rs. 100) = Rs. [(120/100) * (75/100) * 100] = Rs. 90. Decrease = 10%

Question 13

A man spends 35% of his income on food, 25% on children's education and 80% of the remaining on house rent. What percent of his income he is left with ?

Accepted Answer

Let the total income be x. Then, income left = (100 - 80)% of [100 - (35 + 25)] % of x = 20% of 40% of x = [(20/100) * (40/100) * 100] % of x = 8 % of x.

Question 14

Gaurav spends 30% of his monthly income on food articles, 40% of the remaining on conveyance and clothes and saves 50% of the remaining. If his monthly salary is Rs. 18,400, how much money does he save every month ?

Accepted Answer

Saving = 50% of (100 - 40)% of (100 - 30)% of Rs. 18,400 = Rs. (50/100 * 60/100 * 70/100 * 18400) = Rs. 3864.

Question 15

In an election only two candidates contested 20% of the voters did not vote and 120 votes were declared as invalid. The winner got 200 votes more than his opponent thus he secured 41% votes of the total voters on the voter list. Percentage votes of …

Accepted Answer

Let there be x voters and k votes goes to loser then 0.8x - 120 = k + (k + 200) k+200 = 0.41x => k = 1440 and (k + 200) =1640 Therefore 1440/3200 x 100 = 45%

Question 16

405 sweets were distributed equally among children in such a way that the number of sweets received by each child is 20% of the total number of children. How many sweets did each child recieve ?

Accepted Answer

Let the total number of children be x. Then, x * (20% of x) = 405 => x * 20x/100 = 405 1 5 x 2 = 405 => x=45 Number of sweets received by each child = 20% of 45 = 9.

Question 17

If 75% of a number is added to 75, then the result is the number itself. The number is :

Accepted Answer

Let the number be x, Then 75% of x + 75 = x => x - 75x/100 =75 => x = 300 .

Question 18

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

Accepted Answer

Excess of B's height over A's = [(40/(100 - 40)] x 100% = 66.66%

Question 19

A salesman gets commission on total sales at 9%. If the sale is exceeded Rs.10,000 he gets an additional commission as bonus of 3% on the excess of sales over Rs.10,000. If he gets total commission of Rs.1380, then the bonus he received is:

Accepted Answer

Commission up to 10000 = 10000 x 9 100 = 900 Again after 10000, Commission : Bonus 9 : 3 3x : x Therefore, Bonus = 1380 - 900 × 1 4 = R s . 120

Question 20

What percent of 7.2 kg is 18 gms ?

Accepted Answer

Required percentage = (18/7200 * 100)% = 1/4% = 0.25%

Percentage Questions