Chickens and rabbits are kept together. Each has one head; chickens have two legs and rabbits four. There are 35 heads and 94 legs altogether. How many chickens and how many rabbits are there?

A mother squirrel collects 20 pine cones on each sunny day and 12 pine cones on each rainy day. Each day in the period is either sunny or rainy. Over several consecutive days she collects 112 pine cones, averaging 14 pine cones per day. How many of those days were rainy?

There are 35 large and small monkeys picking fruit. The monkey king supervises but does not pick and is not one of the 35. Every worker picks for all eight hours at the stated rates. When the monkey king is absent, one large monkey picks 15 kilograms per hour and one small monkey picks 11 kilograms per hour. When the monkey king is present, every monkey—large or small—picks 12 kilograms more per hour. One day they worked for 8 hours. The monkey king supervised only during the first hour and the last hour, and the monkeys picked 4,400 kilograms altogether. How many small monkeys were in the group?

Six table fans and five ceiling fans cost 1,755 yuan altogether. Each table fan costs 45 yuan more than each ceiling fan. Find the price of one table fan and one ceiling fan.

Fifteen students are divided into two groups for a calligraphy contest. Students in Group 1 write an average of 8 sheets each, and students in Group 2 write an average of 9 sheets each. Together the two groups write 127 sheets. How many students are in each group?

A 155-metre electrical wire is cut into 25 pieces, with no wire lost in cutting. Some pieces are 5 metres long, and the rest are 8 metres long. How many pieces of each length are there?

Places A and B are 460 kilometres apart. Xiao Wang spends 9 hours traveling from A to B, excluding any waiting or transfer time. He travels first by car at 40 kilometres per hour and then by train at 60 kilometres per hour. How many hours does he spend in the car, and how many hours on the train?

A table has 4 legs, and a washbasin stand has 3 legs. There are 100 tables and basin stands altogether, with 340 legs in total. How many tables and how many basin stands are there?

Five tables and ten chairs cost 400 yuan altogether. The price of one table is exactly equal to the price of two chairs. Find the price of one table and one chair.

A zoo has a group of ostriches and giraffes. Every animal has two eyes; each ostrich has two legs and each giraffe four. Altogether they have 30 eyes and 44 legs. How many ostriches and how many giraffes are there?

A teacher gives every student in Class A four sheets of white paper and every student in Class B three sheets, using 716 sheets altogether. If instead every Class A student receives three sheets and every Class B student receives four sheets, 705 sheets are used. How many students are in each class?

A school has 12 dormitory rooms whose capacities total exactly 80 students. A large room holds 8 students, a medium room holds 7 students, and a small room holds 5 students. There is at least one room of each size. Find every possible (medium rooms, small rooms) pair, and show the corresponding number of large rooms in your working.

A test was given 24 times. Adding the number of questions on all 24 tests gives 426; count a question again each time it appears on a test. Each test had either 25, 16, or 20 questions. How many tests had 25 questions?