Question

Rice costing ₹480 is needed for 8 members for 20 days. What is the cost of rice required for 12 members for 15 days

Answer 1

AnswEr :

Rs.540

$\bf{\large{\underline{\underline{\sf{Given\::}}}}}}$

Rice costing Rs.480 is needed for 8 members for 20 days.

$\bf{\large{\underline{\underline{\sf{To\:find\::}}}}}}$

The cost of rice required for 12 members for 15 days.

$\bf{\large{\green{\underline{\underline{\tt{Explanation\::}}}}}}$

$\begin{tabular}{|c|c|c|c|}\cline{1-4}\multicolumn{4}{|c|}{Tabular of quantity}\\ \cline{1-4} Cost of Rice & 480 & x & 480:x\\ \cline{1-4} Number of members & 8 & 12 & 8:12\\ \cline{1-4}Number of day's & 20 & 15 & 20:15 \\ \cline{1-4}\end{tabular}}$

According to the question of direct and Inverse proportion, we get;

$\dashrightarrow\tt{480:x=8:12::20:15}\\\\\\\\\dashrightarrow\tt{480:x=2:3::4:3\:\:\:\:\:\:\:[cancel\:by\:4\:\&\:5]}\\\\\\\\\dashrightarrow\tt{480:x=8:9}\\\\\\\\\dashrightarrow\tt{\dfrac{480}{x} =\dfrac{8}{9} }\\\\\\\\\dashrightarrow\tt{x\:=\:\dfrac{\cancel{480}*9}{\cancel{8} }}\\\\\\\\\dashrightarrow\tt{x\:=\:Rs.(60*9)}\\\\\\\\\dashrightarrow\tt{\green{x\:=\:Rs.540}}$

Hence,

Rs.540 cost of rice required for 12 members for 15 days.

Answer 2

$\huge\bold\green{Answer:-}$

Given:

Cost of rice needed for 20 days for 8 members is 480

To find:  

Cost of rice needed for 15 days for 12 members  

Solution:

The cost of rice for one member for 20 days=

480/8 = Rs.60

Hence, the cost of rice for one member for one day=

60/20 = Rs.3

It takes Rs.3 to feed one member per day with rice.

Cost of rice needed for 12 members=

12 × 3 = Rs.36 for one day.

Cost of rice needed for 12 members for 15 days=

15 × 36 = 540

Hence, cost of rice required for 12 members for 15 days is Rs. 540.