Question

Renu spends 3/7 of her pocket money on purchasing a new Maths book and is left with Rs. 220. Find the cost of the Maths book.

Answer 1

Answer:

hello dear your answer-price of the math book is 165.

step by step explaination:

suppose renu's pocket money is = p

(he spend his 3/7 money of pocket money by purchasing math book and rest pocket money left 220 of whole pocket money.)

so we knew from it that:

math book price+rest pocket money = total pocket money

math book price is 3/7 parts of total pocket money.

we supposed the total money = p

then:

math book price is =3p/7

rest money= 220

math book price + rest money= p

$\frac{3p}{7 } + 220 = p$

• 3p+1540/7=p
• 3p+1540=7p
• 7p-3p=1540
• 4p=1540
• p=1540/4
• p=385

then pocket money (p)=385

Book price is=total amount- rest amount

385-220=165.

for that: math book price is 165.

Answer 2

$\bf{\underline{\underline \blue{Solution:-}}}$

$\sf\underline{\red{\:\:\: AnswEr:-\:\:\:}}$

• The cost of the book = Rs. 165

$\sf\underline{\red{\:\:\: Given:-\:\:\:}}$

• Renu spends $\sf {\dfrac{3}{7} }$ of her pocket money on purchasing a new Maths book and is left with Rs. 220.

$\sf\underline{\red{\:\:\: Need\:To\: Find:-\:\:\:}}$

• The cost of the book = ?

$\bf{\underline{\underline \blue{Explanation:-}}}$

$\dagger \sf {\:\:Portion \:of \:money \:spend\:on \:purchasing \:math \:book = \dfrac{3}{7} }$

$\sf\underline{\green{\:\:\: ThereFore:-\:\:\:}}$

$\sf {The\: portion\:of\:money\:left = 1 - \dfrac{3}{7} }$

$\sf {The\: portion\:of\:money\:left = \dfrac{7 - 3}{7} }$

$\sf {The\: portion\:of\:money\:left = \dfrac{4}{7} }$

$\sf\underline{\green{\:\:\: Since:-\:\:\:}}$

• $\sf {\dfrac{4}{7} }$ of the money = Rs. 220

$\sf\underline{\red{\:\:\: A.T.Q:-\:\:\:}}$

$\dashrightarrow \sf {Total\: money = Rs.\bigg(220 \times \dfrac{7}{4} \bigg)}$

$\dashrightarrow \sf {Total\: money = Rs. \: (55 \times 7)}$

$\dashrightarrow \sf {Total\: money = Rs. \: 385}$

$\sf\underline{\red{\:\:\: Hence:-\:\:\:}}$

$\bigstar \: \boxed{ \sf \: The\:cost\:of\:the\:book = Total\:money - Money\:left}$

$\dashrightarrow \sf {The\:cost\:of\:the\:book = Rs. \:385 - \:Rs. 220}$

$\dashrightarrow \sf {The\:cost\:of\:the\:book = Rs. \: 165}$

$\sf\underline{\green{\:\:\: ThereFore:-\:\:\:}}$

• The cost of the book is Rs. 165

$\rule{200}{2}$