Activity In figure 7.30, side of square ABCD is 7 cm. With centre D and radius p.
sector D - AXC is drawn. Fill in the following boxes properly and finde
the area of the shaded region.
Solution : Area of a square =
(Formula
7
= 49 cm
Area of sector (D- AXC) =
30*3043 (Formula
А
4
Fig. 7.30
7
360
38.5 cm
A (shaded region) = A
-A
cm
cm
cm
Answers
Answer:
Required Solution :–
★ The number of deer = 72 ★
Given:
• Half of a herd of deer are grazing in the field and three-fourths of the remaining are playing.
• The rest 9 are drinking water from the pond.
To calculate:
• The number of deer in the herd.
Calculation:
Let us assume the number of deer in the herd as x.
So, as the question states :
›» Half of a herd of deer are grazing in the field.
\rm \red {\implies Number \: of \: those \: who \: are\: grazing = \dfrac{x}{2} }⟹Numberofthosewhoaregrazing=
2
x
Now,
\implies⟹ Remaining deer = \sf {x -\dfrac{x}{2}}x−
2
x
\implies⟹ Remaining deer = \sf {\dfrac{2x-x}{2}}
2
2x−x
\rm \red {\implies Remaining \: deer = \dfrac{x}{2}}⟹Remainingdeer=
2
x
Also, as the question states :
›» Three-fourths of the remaining are playing.
\implies⟹ Number of those who are playing = \sf {\dfrac{3}{4} \: of \: \dfrac{x}{2} }
4
3
of
2
x
\implies⟹ Number of those who are playing = \sf {\dfrac{3}{4} \times \dfrac{x}{2} }
4
3
×
2
x
\implies⟹ Number of those who are playing = \sf {\dfrac{3 \times x}{4 \times 2} }
4×2
3×x
\rm \red {\implies Number \: of \: those \: who \: are\: playing = \dfrac{3x}{8} }⟹Numberofthosewhoareplaying=
8
3x
And the other 9 deer are drinking, thus
\sf { Total \: number \: of \: deer = \dfrac{x}{2} + \dfrac{3x}{8} + 9 }Totalnumberofdeer=
2
x
+
8
3x
+9
→\sf { x = \dfrac{x}{2} + \dfrac{3x}{8} + 9 }x=
2
x
+
8
3x
+9
→\sf { x = \dfrac{4x+3x+72}{8} }x=
8
4x+3x+72
→\sf { x = \dfrac{7x+72}{8} }x=
8
7x+72
→\sf { x \times 8 = 7x+72 }x×8=7x+72
→\sf { 8x = 7x+72 }8x=7x+72
→\sf { 8x - 7x = 72 }8x−7x=72
→\sf { x = 72 }x=72
\rm \green{ \longrightarrow Total \: number \: of \: deer = 72 }⟶Totalnumberofdeer=72
Therefore, the number of deer in the herd is 72 .