No. XXXV.—ON A BLACKBOARD
To test the powers of his young pupils, Dr Puzzlewitz set the following little problem on his blackboard:—
| A | - | B | = | 4 | ||
| A | ÷ | B | = | 4 | ||
What are the values of A and of B, when 4 is the result of dividing A by B, or of subtracting B from A?