Question

Please answer... its urgent. ​

Answer 1

$\huge \bf \pink{ A} \purple{n} \pink{s} \purple{w} \pink{e} \purple{r}$

We have , Principal , P = Rs 7500

Time , n = 2 yrs

Amount. A = P 1 + R 100 n

⇒ 9075 = 7500 1 + R 100 2

⇒ 9075 7500 = 1 + R 100 2

⇒ 121 100 = 1 + R 100 2

⇒ 11 10 2 = 1 + R 100 2

⇒ 1 + R 100 = 11 10

⇒ R 100 = 11 10 - 1

⇒ R 100 = 11 - 10 10

⇒ R 100 = 1 10

⇒ R = 10 So , rate of interest is 10.

Answer 2

Let,

$\sf \dfrac{21}{x} + \dfrac{47}{y} = 110 \: \: \: \: \: - - - - (1)$

$\sf\dfrac{27}{x} + \dfrac{21}{y} = 162 \: \: \: \: \: - - - - (2)$

On Solving Equation .(1)

${ \: \: \: \: \: \implies \sf \dfrac{21}{x} + \dfrac{47}{y} = 110}$

${ \: \: \: \: \: \implies \sf \dfrac{21y + 47x}{xy} = 110}$

${ \: \: \: \: \: \implies \sf 21y + 47x = 110 xy }$

Multiplying both sides by 27.

${ \: \: \: \: \: \implies \sf 27(21y + 47x) = 27(110 xy) }$

${ \: \: \: \: \: \implies \sf 576y + 1296x = 2970 xy \: \: \: \: \: - - - - (3)}$

On Solving Equation (2)

${ \: \: \: \: \: \implies\sf\dfrac{27}{x} + \dfrac{21}{y} = 162}$

${ \: \: \: \: \: \implies \sf \dfrac{27y + 21x}{xy} = 162}$

${ \: \: \: \: \: \implies \sf 27y + 21x = 162xy }$

Multiplying both sides by 21.

${ \: \: \: \: \: \implies \sf 21(27y + 21x) = 21(162xy) }$

${ \: \: \: \: \: \implies \sf 567y + 441x = 3402xy \: \: \: \: \: - - - - (4)}$

On Subrtracting Equation 3 and 4 .

${ \: \: \: \: \: \implies \sf 567y + 1296x - ( 567y + 441x ) = 2970 xy - (3402xy)}$

${ \: \: \: \: \: \implies \sf \cancel{567y} + 1296x \cancel{- 567y} - 441x = 2970 xy - 3402xy}$

${ \: \: \: \: \: \implies \sf 855x = 432xy}$