Table of Contents
Heights (in cms) | No. of Sticks |
---|---|
15 | 10 |
18 | 16 |
20 | 10 |
22 | 8 |
25 | 7 |
30 | 10 |
Ans. (a) 21·18
Explanation:
Σf = 10 + 15 + 10 + 8 + 7 + 10 = 60
Σfx = 150 + 270 + 200 + 176 + 175 + 300
= 1271
∴ Mean = \frac{\Sigma fx}{\Sigma f} = \frac{1271}{60} =21.18.
Ans. (d) 990 cm^2\\
Explanation:
Radius (r) = \frac{1}{2} × diameter = \frac{21}{2} cm
Height (k) = 15 cm
∴ curnel surface area =2πrh
=2× \frac{21}{7} × \frac{21}{2}×15 \\
= 990 cm^2.
X | 10 | 30 | 50 | 70 | 90 | 110 |
Y | 135 | 187 | 240 | 273 | 124 | 151 |
Explanation:
Let the assumed mean A = 70.
x | f | d= x – A | ft | |
---|---|---|---|---|
10 | 135 | – 60 | – 3 | – 405 |
30 | 187 | – 40 | – 2 | – 374 |
50 | 240 | – 20 | – 1 | – 240 |
A = 70 | 273 | 0 | 0 | 0 |
90 | 124 | 20 | 1 | 124 |
110 | 151 | 40 | 2 | 302 |
Explanation:
Mean =A + \frac{\Sigma ft}{\Sigma f} × i \\
=70+ \begin{pmatrix} \frac{-593}{1110}\end{pmatrix} ×20 = 59.32 ans.
Explanation:
we have
\bar{X} = \frac{x_1+x_2+..+x_n}{n} .....(i)\\
\text{Let} \\
\bar{X} = \text{be the mean of} x_1 + (a,b) x_2+(a-b),..., x_n+(a-b).\\
\text{Then}\\
\bar{X} = \frac{[x_1+(a-b)]+[x_2(a-b)]+..+[x_n(a-b)]}{n} \\
= \frac{x_1+x_2+..+x_n+n(a-b)}{n} \\
= \frac{x_1+x_2+..+x_n}{n} = \frac{n(a-b)}{n} \\
= \bar{X} +(a−b). [Using (i)]
Explanation:
Here, n=10, \bar{X} =1445.
So, \bar{X} = \frac{1}{n}(∑ x_1 ) \\
⇒ n \bar{X} = ∑ x_1 \\
⇒ 10×1445 = ∑ x_1 \\
⇒ ∑ x_1 = 14450.
So, total monthly salary of 10 persons is ₹ 14,450.Monthly salary of one more person who joined the group is ₹ 1,500.
∴ Total monthly salary of 11 persons = ₹14,450 +₹1,500 = ₹15,950
So, average monthly salary of 11 persons= \frac{Total\space monthly\space salery}{11} = \frac{15,950}{11} = ₹ 1,450.
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Download NowChapter No. | Chapter Name |
---|---|
Chapter 1 | Goods and Service Tax (GST) |
Chapter 2 | Banking |
Chapter 3 | Shares and Dividends |
Chapter 4 | Linear inequations |
Chapter 5 | Quadratic Equations in one variable |
Chapter 6 | Ratio and proportion |
Chapter 7 | Factorization |
Chapter 8 | Matrices |
Chapter 9 | Arithmetic Progression |
Chapter 10 | Geometric Progression |
Chapter 11 | Coordinate Geometry |
Chapter 12 | Reflection |
Chapter 13 | Similarity |
Chapter 14 | Loci |
Chapter 15 | Circles |
Chapter 16 | Constructions |
Chapter 17 | Mensuration |
Chapter 18 | Trigonometry |
Chapter 19 | Statistics |
Chapter 20 | Probability |
Chapter Wise Important Questions for ICSE Board Class 10 Mathematics |
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Goods and Service Tax (GST) |
Banking |
Shares and Dividends |
Linear inequations |
Quadratic Equations in one variable |
Ratio and proportion |
Factorization |
Matrices |
Arithmetic Progression |
Geometric Progression |
Coordinate Geometry |
Reflection |
Similarity |
Loci |
Circles |
Constructions |
Mensuration |
Trigonometry |
Statistics |
Probability |
CBSE Important Questions Class 10
ICSE Important Questions Class 10
CBSE Important Questions Class 10
ICSE Important Questions Class 10