I figured the same, but that's a curious definition for "combined their money". That means that Masha has no money, and Misha has six kopecks, so they combined 0 + 6 and are still short of 7. If the price was eight kopecks, they'd have one and seven each, and would have exactly enough. If it cost nine kopecks, they'd have 2 and 8, and would have more than enough.
Eventually I concluded that the price must be between 7 and 8 kopecks, however, a kopeck is a fraction of a ruble, and Google tells me the exchange rate is currently something like 76 rubles per USD, and a kopeck is 1/100th of a ruble, so a tiny fraction of a penny, which is itself nearly worthless. Wikipedia says that hyperinflation in early Soviet Russia, inflation during the cold war, the 1998 redenomination of one new RUB ruble to 1000 RUR old rubles, and subsequent inflation in Russia all combine to mean that one kopeck in the early 90s is worth about 40,000 times less than one kopeck today. Similarly, my American son is sometimes confused why Mom and Dad pay for stuff at stores with dollar bills, but also have pennies, nickels, and dimes. Morris the Moose can buy a lemon drop for a penny, why does a small pack of lemon drops cost two dollars at the store?
The last time you could subdivide a kopeck in half into a denga was around the 1917 revolution, so if the book cost 7 kopecks and one denga, Masha could have one denga and Misha could have 6 kopecks and one denga, and they could combine to get 7 kopecks but not have enough.
The true answer is that if Masha and Misha have been collecting old kopecks forgotten between the couch cushions in their piggybanks, they'll be better off melting the coins for scrap metal, because they're not keeping up with inflation. You can barely buy a piece of paper for a ruble, much less a kopeck. Except the dengas, if they're in good condition, they should sell those to rare coin collectors for on the order of 100,000 kopecks, which is an awfully large number for a five-year-old to be dealing with.
Eventually I concluded that the price must be between 7 and 8 kopecks, however, a kopeck is a fraction of a ruble, and Google tells me the exchange rate is currently something like 76 rubles per USD, and a kopeck is 1/100th of a ruble, so a tiny fraction of a penny, which is itself nearly worthless. Wikipedia says that hyperinflation in early Soviet Russia, inflation during the cold war, the 1998 redenomination of one new RUB ruble to 1000 RUR old rubles, and subsequent inflation in Russia all combine to mean that one kopeck in the early 90s is worth about 40,000 times less than one kopeck today. Similarly, my American son is sometimes confused why Mom and Dad pay for stuff at stores with dollar bills, but also have pennies, nickels, and dimes. Morris the Moose can buy a lemon drop for a penny, why does a small pack of lemon drops cost two dollars at the store?
The last time you could subdivide a kopeck in half into a denga was around the 1917 revolution, so if the book cost 7 kopecks and one denga, Masha could have one denga and Misha could have 6 kopecks and one denga, and they could combine to get 7 kopecks but not have enough.
The true answer is that if Masha and Misha have been collecting old kopecks forgotten between the couch cushions in their piggybanks, they'll be better off melting the coins for scrap metal, because they're not keeping up with inflation. You can barely buy a piece of paper for a ruble, much less a kopeck. Except the dengas, if they're in good condition, they should sell those to rare coin collectors for on the order of 100,000 kopecks, which is an awfully large number for a five-year-old to be dealing with.