Inverse relationship - math problems

Number of problems found: 201

  • Markus painter
    painter Markus used ¾ liter of paint to cover 10 ½ square meters of wall. How many liters of paint is needed to cover 12 ¼ square meters of wall?
  • Strawberries
    jahoda Three people pick strawberries from 48 rows in 8 hours. How many hours do five people need to pick strawberries from 20 rows?
  • The bricklayer
    murar The bricklayer built a six-meter base of the fence in 3 hours. How long does it take to build a 14 m long base?
  • Multiplicative inverse
    inverse Explain why the reciprocal of - 1 1/17 is the multiplicative inverse of - 17/18.
  • Sort fractions
    fractions Which is larger 3/7, 3/8, 3/9, 3/6 =
  • Cornbreads
    tea If 4 and a half teaspoons of baking powder are need to make 10 servings of cornbread, how many teaspoons are needed to make 25 servings?
  • Petrol as fuel
    fuel A car can travel 480 miles on a full tank of petrol. The tank holds 60 litres. The fuel gauge shows there are 15 litres left in the tank. How many more miles can the car travel before it runs out of petrol?
  • Mrs. Zarka
    pie Mrs. Zarka has 3 pies for a party. She calculates that if she splits the pies evenly among the guests, they will each receive 1/6 of a pie. How many guests are there?
  • Ember
    ratios Ember spent $144 on her birthday party for 18 guests. If the cost is at the same rate, how many guests will there if she spends $176?
  • The printer
    time A total of 6 piece of book covers were printed in 0.12 hours. Each piece of the book cover was printed in equal time. Calculate the time, in hours, to print 30 book covers.
  • Six identical
    balloon Six identical compressors inflate 180 balloons in one hour. How many balloons inflate one compressor in 10 minutes?
  • Mushroom risotto
    workers 630g of rice is needed to prepare mushroom risotto for four people. How many boxes of 500g rice do you have to buy to prepare risotto for 17 people?
  • Weighted harmonic average
    workers Ten workers will do some work in 2 minutes, five workers in 10 minutes and three workers in 6 minutes. How many minutes per average worker per worker?
  • Harmonic mean
    means_math If x, y, z form a harmonic progression, then y is the harmonic mean of x and z. Find the harmonic mean of the numbers 6 and 5.
  • Insert 7
    seq Insert five harmonic means between 3 and 18
  • Insert 6
    seq Insert four harmonic means between 3/7 and 3/19
  • Insert 5
    sequence_geo Insert five harmonic means between 1/2 and 1/26
  • Harmonic 4
    mean_normal The harmonic mean of -6 and 5.
  • Harmonic mean
    sequence_geo Harmonic means of 6 and 12
  • HP - harmonic progression
    exp_growth Determine the 10th term of the harmonic progression 6,4,3,…

Do you have an exciting math question or word problem that you can't solve? Ask a question or post a math problem, and we can try to solve it.



We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...