April 2023
Problem of the Month

Pens Problem

A lady in England was stumped by her 10 year old daughter's maths homework, so she put the problem out on Twitter:

There are 5 times as may pens in box A than box B.

Tom moves 76 pens from box A to box B.

Both boxes now have the same number of pens.

How many pens are in box A now?

Solution

The answer is 114 pens.

Let A = number of pens in box A
Let B = number of pens in Box B.

A = 5B
A - 76 = B + 76

So, A = B + 152
5B = B + 152
4B = 152
B = 38   This is the original number of pens in Box B.
Then A = 5*38 = 190   This is the original number of pens in Box A.

So, after moving 76 pens, both Box A and Box B contain 114 pens.

Correctly solved by:

1. K. Sengupta	Calcutta, West Bengal, India
3. Colin (Yowie) Bowey	Beechworth, Victoria, Australia
3. Ritwik Chaudhuri	Santiniketan, West Bengal, India
4. Dr. Hari Kishan	D.N. College, Meerut, Uttar Pradesh, India
5. Brijesh Dave	Mumbai City, Maharashtra, India
6. Davit Banana	Istanbul, Turkey
7. Seth Cohen	Concord, New Hampshire
8. Mohamed Sheriff (MEDDORA)	Freetown, Western area, Sierra Leone, West Africa
9. Ivy Joseph	Pune, Maharashtra, India
10. Carolina Romero	Central High School, Grand Junction, Colorado
11. Colter Tims	Mountain View High School, Mountain View, Wyoming
12. Ellie Barker	Mountain View High School, Mountain View, Wyoming
13. Kelly Stubblefield	Mobile, Alabama

Send any comments or questions to: David Pleacher