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CHAPTER I—EGYPTlAN ARITHMETIC
[25
In the third multiplication, instead of multiplying 7 by 21⁄41⁄8. the author multiplies 21⁄41⁄8 by 7, this being easier. A similar change is made in each of the next three problems. See Introduction, page 6.
Problem 25
A guantity and its 1⁄2 added together become 16. What is the guantity?
Assume 2.
| \ | 1 | 2 |
| \ | 1⁄2 | 1 |
| Total | 3. | |
As many times as 3 must be multiplied to give 16, so many times 2 must be multiplied to give the required number.
| \ | 1 | 3 |
| 2 | 6 | |
| \ | 4 | 12 |
| 2⁄3 | 2 | |
| \ | 1⁄3 | 1 |
| Total | 51⁄3. | |
| 1 | 51⁄3 | |
| \ | 2 | 102⁄3 |
Do it thus:
| The quantity is | 102⁄3 | |
| 1⁄2 | 51⁄3 | |
| Total | 16. |
Problem 26
A quantity and its 1⁄4 added together become 15. What is the quantity?
Assume 4.
| \ | 1 | 4 |
| \ | 1⁄4 | 1 |
| Total | 5. | |
As many times as 5 must be multiplied to give 15, so many times 4 must be multiplied to give the required number. Multiply 5 so as to get 15.
| \ | 1 | 5 |
| \ | 10 | |
| Total | 3. | |
