ML Aggarwal CBSE Solutions Class 7 Math 8th Chapter Percentage and its Application Exercise 8.2
(i) 15% of 250
(ii) 25% of 120 litres
(iii) 1% of 1 hour
(iv) 75% of 1 kg
(v) 120% of Rs. 250
(vi) 0.6% of 2 km
(2) 8% children of a class of 25 like getting wet in the rain. How many children like getting wet in the rain?
(3) Vasundhara ate 3 ice creams cups out of 20 kept in the fridge. What percent did she eat?
SOLUTION Number 1, 2 & 3:
(i) 20 as percentage of 50.
(ii) 60 litres as a percentage of 40 litres
(iii) 90 cm as a percentage of 4.5 m
(iv) 350 g as a percentage of 5.6 kg.
(5) What percent is:
(i) 12 to 80
(ii) 25 paise of 4 rupees
(iii) 300 g of 2 kg
(6) A school team won 6 games this year against 4 games won last year. What is the percent increase?
(7) The price of a shirt decreased from Rs. 80 to Rs. 60, find the percentage of decrease in the price of the shirt.
SOLUTION Number 4, 5, 6 & 7:
(8) My mother says, in her childhood petrol was Rs. 1 per litre. It is Rs. 65 per litre today. Vy what percentage has the prices of petrol gone up?
(9) Rate of basmati rice last year was Rs. 40 a kg. This year they are costly by 20%. What is the price this year?
(10) 300 students took an exam. 28% failed. Calculate the number of students who passed the exam.
(11) Out of 15000 voters in a constituency, 60% voted. Find the number of voters who did not vote.
SOLUTION Number 8, 9, 10 & 11:
(12) 20% of length of a flagpole is painted green, 45% is painted yellow and the remaining red. If the length of the pole is 18 m, what length of it is painted red?
(13) Chalk contains 10% calcium, 3% carbon, 12% oxygen and the remaining sand. Find the amount of carbon and calcium (in grams) in 5/2 kg of chalk. Also find the amount of sand (in kg).
(14) Find the whole quantity if:
(i) 25% of it is 9
(ii) 75% of it is 15
(iii) 12% of it is Rs. 1080
(iv) 8% of it is 40 litres.
(15) Mohini save Rs. 400 from her salary. If this is 10% of her salary, then what is her salary?
(16) 16% of the apples in a basket go bad. If there are 42 good apples in the basket, find the total number of apples in the basket.
SOLUTION Number 12, 13, 14, 15 & 16:
(17) In an examination, a student has to secure 45% marks to pass the exam. If Varun got 251 marks and failed by 19 marks, what are the maximum marks?
(18) On a rainy day, 94% of the students were present in a school. If the number of students absent on that day was 174, find the total strength of the school.
SOLUTION Number 17 & 18:
(19) 40% of the population of a town are men and 39% are women. If the number of children is 12600, find the number of men.
SOLUTION Number 19:
(20) If the price of a watch is increased by 15%, the increase in the price in the number of children is 12600, find the number of men.
(21) (i) Find the number which when increased by 30% becomes 39.
(ii) Find the number which when decreased by 8% becomes 506.
(22) The price of a shirt is reduced by 7% to Rs. 465. What is its original price?
SOLUTION Number 20, 21 & 22: