Question

At a certain fast food restaurant, Amit can buy 3 burgers, 7 shakes and one order of fries for Rs. 120. At the same place, it would cost Rs. 164.50 for 4 burgers, 10 shakes and one order of fries. How much would it cost for an ordinary meal of one burger, one shake and one order of fries?

• A. Rs. $31$
• B. Rs. $41$
• C. Rs. $21$
• D. Cannot be determined

Answer 1

Answer: (A)

Rs. $31$

Let cost of burger = $b$, cost of shake = $s$

and cost of fries = $f$
Now, $3b+7s+f=120$ ...(1)

And $4b+10s+f=164.50$ ...(2)
Subtract the two equations we get

$b+3s=44.5$
$\therefore b=44.5-3s$ ...(3)
Now, $3b+7s+f=120$
or $2b+b+7s+f=120$
$2(44.5-3s)+b+7s+f=120$ ....from (3)
$89-6s+b+7s+f=120$
$\therefore b+s+f=31$
Thus, cost of one burger, one shake and one fries is Rs. $31$.