Question-9061

Question Number 9061 by tawakalitu last updated on 16/Nov/16

Commented by tawakalitu last updated on 16/Nov/16

$$\mathrm{please}\:\mathrm{help}. \\ $$

Answered by mrW last updated on 16/Nov/16

(1) 80∙((1/2))^n =2.5 ((1/2))^n =((2.5)/(80)) 2^n =((80)/(2.5))=32=2^5 n=5 (3) now: son 15, father 15×10/3=50 ((50+x)/(15+x))=(2/1) 50+x=30+2x x=20

$$\left(\mathrm{1}\right) \\ $$$$\mathrm{80}\centerdot\left(\frac{\mathrm{1}}{\mathrm{2}}\right)^{{n}} =\mathrm{2}.\mathrm{5} \\ $$$$\left(\frac{\mathrm{1}}{\mathrm{2}}\right)^{{n}} =\frac{\mathrm{2}.\mathrm{5}}{\mathrm{80}} \\ $$$$\mathrm{2}^{{n}} =\frac{\mathrm{80}}{\mathrm{2}.\mathrm{5}}=\mathrm{32}=\mathrm{2}^{\mathrm{5}} \\ $$$${n}=\mathrm{5} \\ $$$$ \\ $$$$\left(\mathrm{3}\right) \\ $$$${now}:\:{son}\:\mathrm{15},\:{father}\:\mathrm{15}×\mathrm{10}/\mathrm{3}=\mathrm{50} \\ $$$$\frac{\mathrm{50}+{x}}{\mathrm{15}+{x}}=\frac{\mathrm{2}}{\mathrm{1}} \\ $$$$\mathrm{50}+{x}=\mathrm{30}+\mathrm{2}{x} \\ $$$${x}=\mathrm{20} \\ $$

Commented by tawakalitu last updated on 16/Nov/16

$$\mathrm{i}\:\mathrm{really}\:\mathrm{appreciate}\:\mathrm{sir}.\:\mathrm{God}\:\mathrm{bless}\:\mathrm{you} \\ $$

Answered by mrW last updated on 16/Nov/16

(2) 14×17=238cm^2 area cut off: 238−108=130cm^2 14x+(17−x)x=130 x^2 −31x+130=0 (x−5)(x−26)=0 x=5 x=26>14, so it is no solution. hence width of the strips is 5cm. the first strip was 14×5=70cm^2 the second was 12×5=60cm^2 or the first strip was 17×5=85cm^2 the second strip 9×5=45cm^2

$$\left(\mathrm{2}\right) \\ $$$$\mathrm{14}×\mathrm{17}=\mathrm{238}{cm}^{\mathrm{2}} \\ $$$${area}\:{cut}\:{off}:\:\mathrm{238}−\mathrm{108}=\mathrm{130}{cm}^{\mathrm{2}} \\ $$$$\mathrm{14}{x}+\left(\mathrm{17}−{x}\right){x}=\mathrm{130} \\ $$$${x}^{\mathrm{2}} −\mathrm{31}{x}+\mathrm{130}=\mathrm{0} \\ $$$$\left({x}−\mathrm{5}\right)\left({x}−\mathrm{26}\right)=\mathrm{0} \\ $$$${x}=\mathrm{5} \\ $$$${x}=\mathrm{26}>\mathrm{14},\:{so}\:{it}\:{is}\:{no}\:{solution}. \\ $$$${hence}\:{width}\:{of}\:{the}\:{strips}\:{is}\:\mathrm{5}{cm}. \\ $$$${the}\:{first}\:{strip}\:{was}\:\mathrm{14}×\mathrm{5}=\mathrm{70}{cm}^{\mathrm{2}} \\ $$$${the}\:{second}\:{was}\:\mathrm{12}×\mathrm{5}=\mathrm{60}{cm}^{\mathrm{2}} \\ $$$${or}\:{the}\:{first}\:{strip}\:{was}\:\mathrm{17}×\mathrm{5}=\mathrm{85}{cm}^{\mathrm{2}} \\ $$$${the}\:{second}\:{strip}\:\mathrm{9}×\mathrm{5}=\mathrm{45}{cm}^{\mathrm{2}} \\ $$

Commented by tawakalitu last updated on 16/Nov/16

wow . thanks so much sir. i really happy. God bless you.

$$\mathrm{wow}\:.\:\mathrm{thanks}\:\mathrm{so}\:\mathrm{much}\:\mathrm{sir}.\:\mathrm{i}\:\mathrm{really}\:\mathrm{happy}. \\ $$$$\mathrm{God}\:\mathrm{bless}\:\mathrm{you}. \\ $$

Commented by mrW last updated on 16/Nov/16

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