Question

All buys $10$ burgers and $7$ chocolate milkshakes for 50.95$.Ifthepriceofachocolatemilkshakeis$ $0.25$ cheaper than the price of a burger, what is the price of a chocolate milkshake?

• A. 2.85$
• B. 3.10$
• C. 4.05$
• D. 5.09$

Answer 1

The correct option is A 2.85$Letthecostofburgersbe$x$andchocolatemilkshakesbe$y$.

Thus by $1^{st}$ condition,

$10x+7y=50.95$ ....(1)

Second condition says,

$y=x-0.25\Rightarrow x-y=0.25$ ....(2)

Multiply equation (2) by $7$, we get

$7x-7y=1.75$ ....(3)

Add equations (1) and (3), we get

$17x=52.7$

$\Rightarrow x=3.1$

Put this value in equation (1), we get

$10\left(3.1\right)+7y=50.95$

$\Rightarrow 31+7y=50.95$

$\Rightarrow y=2.85$

Therefore, cost of chocolate milkshake is rs. $2.85$.