The array below represents a set of 16 playing cards, with the A's representing Aces:

**
A 3 5 8
10 2 4 9
4 2 7 A
2 5 3 8**

Divide the array into sections of adjacent cards so that the sum of the cards' values in each section will be 21. Each Ace can represent either 1 or 11 and you must determine how many sections are needed.

From Page-a-Day Calendar 2016: Amazing Mind Benders, by Puzzability (Mike Shenk, Amy Goldstein and Robert Leighton), Workman Publishing, NY; puzzle for March 9.

The total is** 74, 10 **below** 84=4*21;**

so there are **4** partitions and one of the aces is **11**, and the other is **1**.

The **4** parts are:

**11,3,5 **from the 1^{st} row** +2 **fr the 2^{nd} row** **

**8 **from** **the 1^{st} row** +4,9 **fr the 2^{nd} row

**10 **from 2^{nd} row** +4 **fr the 3^{rd} row** +2,5 **fr the 4^{th} row

2,7,1 fr the 3^{rd}** **row** +3,8 **fr the 4^{th} row.

** **** **

*Edited on ***March 11, 2016, 9:25 am**