1⁄10 also he can take without difficulty. For 13 he has 1⁄10 of 10 equal to 1, and 1⁄10 of 3, by the table that precedes Problem 1, is 1⁄51⁄10. Finally, 1⁄10 of 1⁄28 is 1⁄280.
In the original our author seems to say that we must multiply 1⁄30 by 1⁄23 to get 2⁄31⁄10. It may be that he did not mean to put a dot (the sign for fraction) over 23, but meant to say, Multiply 1⁄30 by 23 to get 2⁄31⁄10. This is a correct statement but does not explain his solution. Following the method given in the other problems of this group, he should have said, Multiply 1⁄23 by 2⁄31⁄10 to get 1⁄30.
Problem 31
A quantity, its 2⁄3, its 1⁄2, and its 1⁄7, added together, become 33. What is the quantity?
Multiply 12⁄31⁄21⁄7 so as to get 33.
1 | 12⁄31⁄21⁄7 | |
\ | 2 | 41⁄31⁄41⁄28 |
\ | 4 | 91⁄61⁄14 |
\ | 8 | 181⁄31⁄7 |
1⁄2 | 1⁄21⁄31⁄41⁄14 | |
\ | 1⁄4 | 1⁄41⁄61⁄81⁄28 |
Total 141⁄4. 141⁄4 times 12⁄31⁄21⁄7 makes 321⁄2 plus the small fractions 1⁄71⁄81⁄141⁄281⁄28. 321⁄2 from 33 leaves the remainder 1⁄2 to be made up by these fractions and a further product by a number yet to be determined.
1⁄71⁄81⁄141⁄281⁄28
taken as parts of 42 are
651⁄4311⁄211⁄2
making in all 171⁄4, and requiring 31⁄21⁄4 more to make 21,1⁄2 of 42.
Take 12⁄31⁄21⁄7 as applying to 42:
\ | 1 | 42 |
\ | 2⁄8 | 28 |
\ | 1⁄2 | 21 |
\ | 1⁄7 | 6 |
Total | 97. |
That is, 12⁄31⁄21⁄7 applied to 42 gives 97 in all. 1⁄42 of 42, or 1, will be 1⁄97 of this, and 31⁄21⁄4 will be 31⁄21⁄4 times as much. Therefore we multiply 1⁄97 by 31⁄21⁄4.
[1]\ | 1⁄97 | 1⁄42 | or | 1 | as | a | part | of | 42 |
\ | 1⁄561⁄6791⁄776 | 1⁄21 | " | 2 | " | " | " | " | 42 |
\ | 1⁄194 | 1⁄84 | " | 1⁄2 | " | " | " | " | 42 |
\ | 1⁄388 | 1⁄168 | " | 1⁄4 | " | " | " | " | 42 |
- ↑ These multiplications do not represent the multiplication of 1⁄97, by 31⁄21⁄4, but form a continuation of the multiplication at the beginning of the solution. But the partial products of