Question

Printer A prints 36 pages every 1.5 minutes. Printer b prints 114 pages every 3 minutes printer c prints 115 pages every 5 minutes which printer prints the fastest?

Answer 1

Printer B prints faster

Solution:

Given that Printer A prints 36 pages every 1.5 minutes

Let "x" be the number of pages printed in 1 minute

Therefore,

1.5 minutes = 36 pages

1 minute = x pages

By cross-multiplication,

$1.5 \times x = 36 \times 1\\\\x = \frac{36}{1.5} = 24$

Thus unit rate of Printer A is: In 1 minute, Printer A can print 24 pages

Printer B prints 114 pages every 3 minutes

Similarly,

3 minutes = 114 pages

1 minute = x pages

This forms a proportion. Therefore by crossmultiplying we get,

$3 \times x = 114 \times 1\\\\x = \frac{114}{3} = 38$

Thus unit rate of Printer B is: In 1 minute, Printer B can print 38 pages

Printer C prints 115 pages every 5 minutes

Similarly,

5 minutes = 115 pages

1 minute = x pages

This forms a proportion. Therefore by crossmultiplying we get,

$5 \times x = 1 \times 115\\\\x = \frac{115}{5} = 23$

Thus unit rate of Printer C is: In 1 minute, Printer C can print 23 pages

unit rate of printer B > unit rate of printer A > unit rate of printer C

On comparing the unit rate of Printer A, B, C we see that, printer B prints faster