Question

2. The strength of a school is 1800. If 55% of the students are girls, then how many
boys are in the school?
3. 35% of the population of a town are men and 40% are women. If the number of
children is 20000, find the number of women.​

Answer 1

$\star\;{\underline{\underline{\bf{\purple{QuesTion\;1\;:}}}}}$

The strength of a school is 1800. If 55% of the students are girls, then how many

boys are in the school?

$\rule{150}{3}$

$\sf GivEn = \begin{cases} & \text{The strength of a school is 1800.} \\ & \text{55 \% of the students are girls. } \end{cases}$

$\underline{\bigstar\:\boldsymbol{Now,\: According\:to\:QuesTion\::}}$

No. of girls = Percentage of girls concerned into school

$\dashrightarrow\sf No. \;of \;girls \dfrac{1800}{100} \times 55 = \bf{990}\\\\\dag\;{\underline{\sf{\pink{So,\;no.\;of\;girls\;are\;990.}}}}$

As we know that,

Total number of student = No. of boys + No. of girls

$\dashrightarrow\sf 1800 = No.\;of\;boys\; + 990\\\\\dashrightarrow\sf No.\;of\;boys\; = 1800 - 990\\\\\dashrightarrow\sf No.\;of\;boys\; = \bf{810}\\\\\dag\;\sf \underline{So,\;no.\;of\;boys\;are\;810.}\\\\\underline{\bigstar\:{\sf{\blue{In\; Percentage\::}}}}\\\\\dashrightarrow\sf \dfrac{810}{1800} \times 100 = \bf{45\%}\\\\\dag\;{\underline{\sf{\pink{Hence,\;No.\;of\;boys\;are\;810\;and\;the\;Percentage\;of\;boys\;are\;45\%.}}}}$

$\rule{200}{4}$

$\star\;{\underline{\underline{\bf{\purple{QuesTion\;2\;:}}}}}$

35% of the population of a town are men and 40% are women. If the number of

children is 20000, find the number of women.

$\rule{150}{3}$

$\sf GivEn = \begin{cases} & \text{35 \% of the population of a town are men.} \\ & \text{40 \% of the population of a town are women.} \\ & \text{The number of</p><p>children is 20000.}} \end{cases}$

☯ Let the no. of men be x.

$\underline{\bigstar\:\boldsymbol{Now,\: According\:to\:QuesTion\::}}$

$\bullet\;\sf Men = \bf{35\%}\\\\\bullet\;\sf Women = \bf{40\%}\\\\\therefore\sf\; Total\; population = (35\% + 40\%) = \bf{75\%}\\\\\bullet\;\sf Children = (100\%- 75\%) = \bf{25\%}$

Therefore,

25% of x be = $20000 \times \cancel{ \dfrac{100}{25}}$

$\dashrightarrow\sf x = \bf{80000}$

$\underline{\bigstar\:{\sf{\blue{Now,\;we\;have\;to\;find\; Population\;of\;women\::}}}}$

$\dashrightarrow\sf \dfrac{40}{100} \times 80000\\\\\dashrightarrow\bf 32000\\\\\dag\;{\underline{\sf{\pink{Hence,\;No.\;of\;women\;are\;32000.}}}}$