AbdurRakib wrote:

A worker carries jugs of liquid soap from a production line to a packing area, carrying 4 jugs per trip. If the jugs are packed into cartons that hold 7 jugs each, how many jugs are needed to fill the last partially filled carton after the worker has made 17 trips?

A. 1

B. 2

C. 4

D. 5

E. 6

The trap: leftover jugs and/or empty spaces in one carton.

(1) Focus first on total number of jugs carried

Ignore the "7 jugs per carton" for now. It's crazy-making.

Instead, start by finding the

total number of jugs carried by the worker in 17 trips

(4 jugs per trip) * (17 trips) =

68 jugs were carried

(2) Filled cartons? Partly filled cartons?

Now calculate how many cartons have been filled, and whether there are any partly filled cartons.

There must be 7 jugs in each carton

Divide 68 by 7 to get the number of cartons that are FULL, but pay attention to the remainder

\(\frac{68}{7}\)= 9 +

remainder 5 jugs

So 9 cartons are full of 7 jugs, and

one carton has

only 5 in it. It needs

2 more.

Answer B

_________________

The only thing more dangerous than ignorance is arrogance.

-- Albert Einstein