Question

The ratio of cost of pen to cost of pencil is 31:51 and the total cost of pen
and
pencil is 41. Find the cost of pen.
​

Answer 1

Answer:

let the cost of pen be 31x

pencil be 51x

total cost = 31x + 51x

41 = 82x

41/82 = x

1/2 = x

Cost of pen = 31 x 1/2

= 15.5

Answer 2

Answer:

$let \: the \: cost \: of \: pen \: be {31}{x} \\ pencil \: be \: {51}{x}$

$total \: cost \: = 31x + 51x$

$41 = 82x$

$x = \frac{41}{82}$

$x = \frac{1}{2}$

$cost \: of \: pen = 31 \times \frac{1}{2} = 15.5$