Question

James bought 22 candy bars for $137. If the king size candy bars cost $8 and a regular size candy bar cost $5 , how many of each candy bar did he buy? One equation looks like: x + y= 22 Find the other equation and solve the system.

Answer 1

Given:

James bought 22 candy bars for $137.

If the king size candy bars cost $8 and a regular size candy bar cost $5.

To find:

The system of equation and solution of it.

Solution:

Let x be the number of king size candy and y be the number of regular size candy.

Quantity: $x+y=22$           ...(i)

Cost : $8x+5y=137$        ...(ii)

Multiply the equation (i) by 5.

$5x+5y=110$           ...(iii)

Subtract (iii) from (ii).

$8x+5y-5x-5y=137-110$

$3x=27$

$x=9$

Put x=9 in (i).

$9+y=22$

$y=22-9$

$y=13$

Therefore, number of king size candy is 9 and number of regular size candy  is 13.