“The old brute is interrupting the lesson,” thinks Ziboroff. “Sitting over us like an inspector—I hate to be bossed! Now, then!” he cries to Pete. “You must learn that same lesson over again for next time. Next we’ll do some arithmetic. Fetch your slate! I want you to do this problem.”
Pete spits on his slate and rubs it dry with his sleeve. His tutor picks up the arithmetic and dictates the following problem to him.
“‘If a merchant buys 138 yards of cloth, some of which is black and some blue, for 540 roubles, how many yards of each did he buy if the blue cloth cost 5 roubles a yard and the black cloth 3?’ Repeat what I have just said.”
Peter repeats the problem and instantly and silently begins to divide 540 by 138.
“What are you doing? Wait a moment! No, no, go ahead! Is there a remainder? There ought not to be. Here, let me do it!”
Ziboroff divides 540 by 138, and finds that it goes three times and something over. He quickly rubs out the sum.
“How queer!” he thinks, ruffling his hair and flushing. “How should it be done? H’m—this is an indeterminate equation and not a sum in arithmetic at all——”
The tutor looks in the back of the book and finds that the answer is 75 and 63.
“H’m—that’s queer. Ought I to add 5 and 3 and divide 540 by 8? Is that right? No that’s not it. Come, do the sum!” he says to Pete.
“What’s the matter with you? That’s an easy problem!” cries Udodoff to Peter. “What a goose you are, sonny! Do it for him, Mr. Ziboroff!”