Question

IF 50 ORANGES COST Rs.70 , WHAT IS THE COST OF 90 ORANGES ??​

Answer 1

Answer:

RS 106

cost of 50 oranges=Rs70

so,cost of 1 Orange =70/50

and cost of 90 oranges =70/50×90

630/5= Rs 106

Answer 2

$\mathfrak{\large{\underline{\underline{Answer :-}}}}$

The cost of 90 oranges is Rs. 126

$\mathfrak{\large{\underline{\underline{Explanation :-}}}}$

Given :

50 oranges cost = Rs. 70

To find :

The cost of 90 oranges

Solution :

$\textbf{Method I}$

Consider the cost of 90 oranges as x

By Proportion :

50 : 70 : : 90 : x

Mean Terms = 70 and 90

Extreme Terms = 50 and x

$\boxed{\sf{Mean \times Mean\:Terms = Extreme \times Extreme \:Terms}}$

$\sf{\implies} \: 70 \times 90 = 50 \times x$

$\sf{\implies} \: 6300 = 50x$

$\sf{\implies} \: x = \dfrac{6300}{50}$

$\sf{\implies} \: x = 126$

$\therefore$ The cost of 90 oranges is Rs. 126

$\rule{300}{1.5}$

$\textbf{Method II}$

By Unitary Method :

★ Cost of One Orange =

$\sf{\implies} \: 70 \div 50$

$\sf{\implies} \: 1.4$

★ Cost of 90 Oranges =

$\sf{\implies} \: 1.4 \times 90$

$\sf{\implies} \: 126$

$\therefore$ The cost of 90 oranges is Rs. 126