Prakrit bought a pack of paper for $5.69 and printer toner for $9.76. He paid with a $20 bill. What was his change?

2 Answers
Nov 1, 2016

The change that Prakrit received was #$4.55#. See Explanation.

Explanation:

Prakrit bought a pack of paper for $5.69 and printer toner for $9.76. He paid with a $20 bill.

Okay, so the problem tells us that Prakrit bought:
Paper: #$5.69#
Printer Toner : #$9.76#

First, let's add these two together:
#$5.69+$9.76=$15.45#

So we know that Prakit would have to pay a total of #$15.45#. But Prakit has a #$20# bill--he doesn't carry all that change around:)

So let's subtract #$15.45# from #$20# in order to see what the cashier gave Prakrit back.

#$20-$15.45=$4.55#

So the change that Prakrit got back was #$4.55#.

Hope this helps!

Nov 4, 2016

I do not know your level of understanding so I am going for the whole thing! If the problem is difficulty in converting the words into numeric presentation then please accept my apologies.

Change # =$4.55#

Explanation:

#color(blue)("Determine total cost")#

Paper # color(white)("d")->$5.69#
Toner# color(white)("d.")->ul($9.76)color(brown)( larr" Add")#
#color(white)("dddddddd")ul($15.45)#

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Determine total change given")#

Offered cash# color(white)("d")$20.00#
Cost# color(white)("ddddddd")ul($15.45)color(brown)( larr" Subtract"#

Note that 20 is the same 1 ten + 10 units so you can write 20 as #cancel(2)^1cancel(0)^(10)# giving

Offered cash# color(white)("d")$cancel(2)^1cancel(0)^(10).00#
Cost # color(white)("ddddd.d")ul($1color(white)(..)5color(white)("....")color(white)().45)color(brown)( larr" Subtract"#

But this still gives a problem as we have 00 above 45
Ok lets move 1 unit into the tenths column. So #cancel(0)^10# become #cancel(0)^9# giving:

~~~~~~~~~~~~~~~~~~~~~~~

Offered cash# color(white)("d")$cancel(2)^1cancel(0)^(9).cancel(0)^(10)0#
Cost# color(white)("ddddddd")ul($1color(white)(..)5 color(white)("d").color(white)(.)4 color(white)(".d")5)color(brown)( larr" Subtract"#

But we still have a problem with #0#
#color(white)("ddddddddddddddddddddddd.")5#

So lets do the same thing again giving:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Offered cash# color(white)("d")$cancel(2)^1cancel(0)^(9).cancel(0)^(9)cancel(0)^(10)#
Cost# color(white)("ddddddd")ul($1color(white)(..)5 color(white)("d").color(white)(".")4color(white)("d.")5)color(brown)( larr" Subtract"#
#color(brown)("Now we are ready to do the subtraction")#

The answer is: #color(white)(.)$4.55#

#color(green)("With practice you should be able to do this calculation type quite fast")#