Question

Para embalar una caja se emplea 4,2 m de cinta adhesiva. ?Cuántas cajas se podrán embalar con tres rollos que tienen 3 hm, 7 dam y 50 m cada uno?

Answer 1

For this case, we perform the conversions:

First roll:

$1 \ Hectometer --------> 100 \ meters\\3 \ Hectometer --------> x$

$x = \frac {3 * 100} {1}\\x = 300 \ meters.$

We make a rule of three to determine the number of "c" boxes that can be packed with 300 meters of adhesive tape.

1 -----------> 4.2

c -----------> 300

$c = \frac {300 * 1} {4.2}\\c = 71.42857143\\c = 71$

You can pack 71 boxes.

Second roll:

$1 \ Decametro --------> 10 \ meters\\7 \ Decameter --------> x\\x = \frac {7 * 10} {1}\\x = 70 \ meters.$

We make a rule of three to determine the number of "c" boxes that can be packed with 70 meters of adhesive tape.

1 -----------> 4.2

c -----------> 70

$c = \frac {70 * 1} {4.2}\\c = 16.66666667\\c = 16$

You can pack 16 boxes.

Third roll:

1 -----------> 4.2

c -----------> 50

$c = \frac {50 * 1} {4.2}\\c = 11.9047619\\c = 11$

You can pack 11 boxes.

Thus, in total you can pack$11 + 16 + 71 = 98 \ boxes$

Answer:

98 boxes