Reading records
Lucy, Tereza, and Petra decided to compile the compulsory reading records together. It would take 30 days for Lucia alone, 36 for Tereza, and 45 for Petra. How long will it take to make records if they will work together?
Correct answer:
Tips for related online calculators
Looking for calculator of harmonic mean?
Looking for a statistical calculator?
Need help calculating sum, simplifying, or multiplying fractions? Try our fraction calculator.
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
Do you want to convert time units like minutes to seconds?
Looking for a statistical calculator?
Need help calculating sum, simplifying, or multiplying fractions? Try our fraction calculator.
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
Do you want to convert time units like minutes to seconds?
You need to know the following knowledge to solve this word math problem:
Units of physical quantities:
Themes, topics:
Grade of the word problem:
Related math problems and questions:
- Two persons
Two persons are walking beside a railway track at respective speeds of 2 and 4 km per hour in the same direction. A train came from behind them and crossed them in 90 and 100 seconds, respectively. Find the length of the train. - 20 men
20 men are supposed to complete a work in 10 days. After working for 5 days, they realize that only one-fourth of the work is done. How many more men they need to employ to complete the work on time? - Offset the mean
The mean of 16 numbers is 8. If 2 is added to every number, what will be the new mean? - Paul makes
Paul makes a cuboid of plasticine of sides 5 cm, 2 cm, 5 cm. How many such cuboids will he need to form a cube?
- To percentages
Convert the following ratios to percentages. (a) 3 : 4 (b) 2 : 3 (c) 5/8 (d) 15/16 - Overtime and salary
An employee earns R150 per hour and the agreed normal working hours are 45 hrs per week. Overtime is paid at 1 1/2 of the normal rate. If Dave works 52 hrs during the first week of March. What will the total earnings for that particular week be? - Double sides
If each side of a triangle is doubled then find the ratio of the area of new triangle thus formed and the given triangle. - Taps and a tank
A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely? - Manday, manhour
Job problem: 10 men can make 20 toys in 12 days working 12 hours a day.Then, in how many days can 24 persons make 32 toys working 16 hours a day?
- Tricky result
Classic adding with percentages: Evaluate 28% of 450 + 45% of 280 - Two chords 6
A chord PQ is 10.4cm long and its distance from the centre of a circle is 3.7cm. Calculate the length of a second chord RS which is 4.1cm from the centre of this circle. - Numerator and denominator
If the numerator of a fraction is increased by 200% and the denominator of the fraction is increased by 150%, the resultant fraction is 9/35. What is the original fraction? - Two coins
Two coins are tossed simultaneously. What is the probability of getting (i) At least one head? (ii) At most one tail? (iii) A head and a tail? - Katy bought
Katy bought 4/5 kg of oranges, 2 1/2 kg of bananas and 1 1/2 kg of apples everyday. How many kilogram of fruits did she buy each day.
- Walnuts 2
There are 6 2/3 pounds of walnuts in a container, which will be divided equally into containers that hold 1 1/2 pounds. How many containers walnuts will fill? - Calculate 83366
Calculate the side a of triangle ABC if we know va=8cm, b=16cm, vb=10cm. - Representing 83365
30 women work in the police department, representing 60% of the workforce. How many work in the men's department?