Question

For what number of days, $x$$,willthetotalcostofbuyingthematerialsandrentingthetoolsfromstore$B$belessthanorequaltothetotalcostofbuyingthematerialsandrentingthetoolsfromStore$A$ ?

• A. $x\le 6$
• B. $x\ge 6$
• C. $x\le 7.3$
• D. $x\ge 7.3$

Answer 1

The correct option is A $x\le 6$

Since $y=M+(W+K)x$

The total cost $y$ for buying the materials and renting the tools in terms of the number of days, $x$, from store $A$ is $y=750+(15+65)x$ that is $y=750+80x$.

Similarly, the total cost $y$ for buying the materials and renting the tools in terms of the number of days, $x$, from store $B$ is $y=600+(25+80)x$ that is $y=60+105x$.

Since the total cost of buying the materials and renting the tools from store $B$ is less than or equal to the total cost of buying the materials and renting the tools from store $A$, therefore,

$105x+60\le 80x+750$

$\Rightarrow 105x-80x\le 750-60$

$\Rightarrow 25x\le 150$

$\Rightarrow x\le 6$