Three friends – Peter, Ryan and Sarah – are university students, each studying a different subject from one of the following: mathematics, physics or chemistry. If Peter is the mathematician then Sarah isn’t the physicist. If Ryan isn’t the physicist then Peter is the mathematician. If Sarah isn’t the mathematician then Ryan is the chemist. Can you determine which subject each of the friends is studying?
In the first pencil case, there is a lilac pen, a green pencil and a red eraser; in the second – a blue pen, a green pencil and a yellow eraser; in the third – a lilac pen, an orange pencil and a yellow eraser. The contents of these pencil cases are characterised by such a pattern: in every two of them exactly one pair of objects coincides in color and purpose. What should lie in the fourth pencil case, so that this pattern is preserved? (In each pencil case, there are exactly three objects: a pen, a pencil and an eraser.)
Decipher the puzzle:
Decipher the puzzle: \(KIS + KSI = ISK\). The same letters correspond to the same numbers, different letters correspond to different numbers.
Two tribes live on the island: natives and newcomers. It is known that the natives always tell the truth and the newcomers always lie. A traveler hired an indigenous islander as a guide. On the way, they met a man. The traveler asked the guide to find out which tribe this person belongs to. The guide returned and said that the man said that he was a native. Who was the guide – a native or a newcomer?
Among 40 containers there are two containers of different shapes and two containers of different colors. Prove that among them there are two containers that are both of different shapes and colors.
The vendor has a cup weighing scales with unequal shoulders and weights. First he weighs the goods on one cup, then on the other, and takes the average weight. Does he deceive customers?
Teams A, B, C, D and E participated in a relay. Before the competition, five fans expressed the following forecasts.
1) team E will take 1st place, team C – 2nd;
2) team A will take 2nd place, D – 4th;
3) C – 3rd place, E – 5th;
4) C – 1st place, D – 4th;
5) A – 2nd place, C – 3rd.
In each forecast, one part was confirmed, and the other was not. What place did each team take?
In the race of six athletes, Andrew lagged behind Brian and two more athletes. Victor finished after Dennis, but before George. Dennis beat Brian, but still came after Eustace. What place did each athlete take?
Three friends were at the prom dressed in white, red and blue dresses. Their shoes were of the same three colors. Only Sarah’s shoes and dress were of the same color. Laura was wearing white shoes. Neither the dress nor the shoes of Linda were red. Identify the colors of the dresses and of the shoes of the three friends.