Question

3. A bag contains * 1,600 in the form of 10 and 320 notes. If the ratio between the
numbers of 10 and 20 notes is 2: 3; find the total number of notes in all.
Two poles of different heights are standing vertically on a horizontal field
A+​

Answer 1

Step-by-step explanation:

let number of 10 rupee note is 2x and number of 20 rupee note is 3x

value of 10 rupee note is Rs 2x.10

value of 20 rupee note is Rs 3x.20

so,

2x.10+3x.20=1600

=>20x+60x=1600

=> 80 x=1600

=> x=1600/80=20

number of 10 rupee note is 2.20=40

number of 20 rupee note is 3.20=60

total number of notes is (40+60)=100

Answer 2

$\huge \sf \underline \red{Answer : }$

$\sf \underline{ \therefore \: Total \: number \: of \: notes = 100}$

$\sf \underline{ \therefore \: length \: of \: bigger \: pole = 11.25m }$

$\huge \sf \underline \blue{To \: find : }$

• Total number of notes

$\huge \sf \underline \pink{solution : }$

$\sf \underline{Given \: 10 \: and \: 20 \: notes \: is \: 2 : 3}$

↝$\sf{Let \: number \: of \: 10 \: notes \: be \: 2x}$

↝$\sf{Let \: number \: of \: 20 \: notes \: be \: 3x}$

↝$\sf{10 \: notes \: = 2x \times 10 = 20x}$

↝$\sf{20 \: notes = 3x \times 20 = 60x}$

$\sf \underline{Given \: Total \: money \: in \: bag = 1600}$

$\sf \underline{So \: Now,}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf⇢{20x + 60x = 1600}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf⇢{80x = 1600}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf⇢{x = \dfrac{1600}{80} }$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf⇢{x = 20}$

$\star \: \sf {number \: of \: 10 \: notes = 2x = 40}$

$\star \: \sf {number \: of \: 20 \: notes = 3x = 60}$

$\sf \underline{ \therefore \: Total \: number \: of \: notes = 40 + 60 = 100}$

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$\sf \huge \underline \red{Correct \: Question }$

Two poles of different heights are standing vertically on a horizontal field. At a particular time, the ratio between the lengths of their shadows is 2:3. If the height of the smaller pole is 7.5, find the height of the other pole.

$\huge \sf \underline \blue{To \: find : }$

• height of other pole

$\huge \sf \underline \pink{solution : }$

$\sf \underline {Given}$

$\sf{ratios \: of \: their \: shadow \: is \: 2 : 3}$

$\sf{Length \: of \: smaller \: pole = 7.5m}$

$\sf{Let \: height \: of \: bigger \: pole \: be \: x}$

$\: \: \: \: \: \: \: \: \implies \sf{7.5 : x : : 2 : 3}$

$\: \: \: \: \: \: \: \: \implies \sf{7.5 x = 23}$

$\: \: \: \: \: \: \: \: \implies \sf{x = 7.5 \times 23}$

$\: \: \: \: \: \: \: \: \implies \sf{x = 11.25m}$

$\sf \underline{ \therefore \: length \: of \: bigger \: pole = 11.25m }$