R.S Aggarwal Class 8 Chapter 9 Percentage Test Paper Solution
The 9th Chapter of RS Aggarwal book of Class 8 is on Percentage and in this post we have provided complete written solution for the test paper 9 . The solutions are prepared by our team of expert teachers.
Complete RS Aggarwal solution for class 8 is also available in our website.
TEST PAPER-9
A) 1) Express:
(i) 24% as a fraction:
Ans: 24% = 24/100 = 6/25
(ii) 105% as a decimal;
Ans: 105% = 105/100 = 1.05
(iii) 4: 5 as a percentage:
Ans: 4:5 = (4/5) = (4/5) × 100% = 80%
(iv) 56% as a ratio.
Ans: 56% = 56/100 = 14/25 = 14:25
2) If 34% of a number is 85, find the number.
Ans: Let the number be n
34% of n = 85
Or, 34n/100 = 85
Or, n = 250
The required number is 250.
3) The value of a machine depreciates every year by 10%. If the present value of the machine is 54000, what was its value last year?
Ans: Let us assume that the value of the machine was v last year.
∴ v × 90% = 54000
Or, v = 60000
So the cost of the machine last year was 60000.
4) An alloy contains 30% copper, 42% nickel and rest zinc. Find the mass of zinc in 1 kg of alloy.
Ans: According to the question the allow contains 30% copper, 42% nickel and rest is zinc so the percentage of zinc in the alloy should be 100% – (30% + 42%) = 28%
So in 1 kg of allow the mass of the zinc is
1kg×28% = 1000 gm × 28% = 280 gm
5) In a class, 60% of the total numbers of students are boys and there are 14 girls. How many students are there in the class?
Ans: According to the question 60% of the total students are boys so the 40% of them would be girls.
So according to the question
40% of the total students = 14
∴ The total number of students = 35
So we can say that there are a total of 35 students in the class.
6) Which is largest in 8(1/3) %, (4/25) and 0.15?
Ans: 8(1/3)% = 8.333/100 = 0.08333
4/25 = 0.16
And 0.15
Among the three 4/25 is the largest.
B) Mark (✔) against the correct answer in each of the following:
7) What per cent of 2/9 is 1/45?
a) 2.5%
b) 5%
c) 7.5%
d) 10% (✔)
Ans: Let us assume that p% of 2/9 is 1/45
∴ p% × 2/9 = 1/45
Or p% = 1/10
∴ p = 10 %
So, 10% of 2/9 is 1/45
8) A number decreased by 30% gives 84. The number is
a) 90
b) 110
c) 120 (✓)
d) 135
Ans:
Let us assume that the original number be n, which was decreased by 30% to give 84.
∴ n×(100% – 30%) = 84
Or, n 70% = 84
Or, n = 120
The original number is 120.
9) (?)% of 320 is 48?
a) 25%
b) 15% (✓)
c) 14%
d) 9%
Ans: According to the problem
(m) % × 320 = 48
Or, m% × 320 = 48
Or, m% = 3/20
Or, m = 15%
So the required percentage is 15%
10) What per cent of 45 is 54?
a) 83(1/3)%
b) 104%
c) 108%
d) 120% (✓)
Ans: Let us assume that n% of 45 is 54.
So, n%×45 = 54
Or, n = 120%
So, 120% of 45 is 54.
11) A number exceeds 25% of itself by 60. The number is
a) 75
b) 45
c) 80 (✓)
d) 65
Hint. [x – (25x/100)] = 60
Ans:
[x – (25x/100)] = 60
Or, 100x – 25x = 6000
Or, 75x = 6000
Or, x = 80
12) 5% of which number is 12?
a) 120
b) 180
c) 240 (✓)
d) 320
Ans:
Let us assume that the number is p
∴ 5% of p = 12
Or, p/20 = 12
Or, p = 240
C) 13) Fill in the blanks.
i) 7(1/2)% of ₹1200 = ……..
Ans: 7.5% × ₹1200 = (75/10)×(1/100)×1200 = 90
∴ 7(1/2)% of ₹1200 = 90
ii) 240 mL is ……..% of 3L
Ans: we know that 3L = 3000 mL
Now (240/3000) × 100% = 8%
∴ 240 mL is 8% of 3L
iii) If x% of 35 is 42, then x = ……….
Ans: x% of 35 = 42
Or, x% = 6/5
Or, x = 120 %
x% of 35 is 42, then x = 120
iv) 12/5 = ……….%
Ans: (12/5) × 100 = 240%
v) 120 = (……)% of 80
Ans: 120 = m% of 80
Or, m% = 3/2
Or, m = 150%
∴ 120 = 150% of 80
D) 14) Write ‘T’ for true and ‘F’ for false for each of the following:
i) 6% of 8 is 48 (F)
Ans: 8 × 6% = 0.48
The given statement is false.
ii) 6:5 = 30% (F)
Ans: [(6/5) × 100]% = 120%
The given statement is false.
iii) 3/5 = 60% (T)
Ans: [(3/5)×100]% = 60%
The given statement is True.
iv) 6 hours = 25% of a day. (T)
Ans
Total hours in a day = 24 hours
[(6/24)× 100] % = 25%
The given statement is True.