Czech coins

John has 540 CZK, but he has 10 CZK coins and 20 CZK coins only, we knows that he has 10CZK coins 7times more that 20CZK coins, how many 10CZK coin and how many 20CZK coins he saved?

Correct answer:

a =  42
b =  6

Step-by-step explanation:


10a+20b=540
a=7b

10•a+20•b=540
a=7•b

10a+20b = 540
a-7b = 0

a = 42
b = 6

Our linear equations calculator calculates it.



Did you find an error or inaccuracy? Feel free to write us. Thank you!






avatar




Tips to related online calculators
Do you have a system of equations and looking for calculator system of linear equations?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions:

  • Coins
    mince The boy collected coins with value 5 CZK and 2 CZK when he had 50 pieces saved 190 CZK. How many he has each type of coin?
  • Saving
    2kc Paul saves 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins?
  • Sisters
    sestry20091 Sisters Janka and Danka are saved together 220 CZK. On a trip to Janka wants to take a fifth of her savings and Danka's quarter. Then they will have 50 CZK on the trip. How much money saved Janka and Danka?
  • CZK coins
    CZK-coins Thaddeus and Jolana together have 15 CZK. Jolana has half of Thaddeus money. Nevertheless Jolana has 3 coins and Thaddeus 2 coins. Which coin has Thaddeus and Jolana (Help: CZK coins has values 1,2,5,10,20,50 CZK)?
  • Remuneration
    cnb Total remuneration for workers is 47 000 CZK. The second worker received 20% more than the first and third 4000 CZK less than a second employee. How many CZK each received?
  • Birthday
    spice Mother bought 21 desserts on the occasion of Mirka's birthday one tips was 9 CZK and the kremlin cost 12 CZK. For all desserts, she paid 213 CZK. How many kremlins and how many tips mums did buy?
  • Sweets
    Caramelos We want to prepare 5 kg of sweets for 150 CZK. We will mix cheaper candy: 1 kg for 120 CZK and more expensive candy: 1 kg per 240 CZK. How much of these two types of candy is necessary to prepare this mixture?
  • Average monthly salary
    penize A total of 10 teachers work at one small school in Moravia. The monthly salary of each is 21,500 CZK or 21,800 CZK or 22,500 CZK according to their education and age. The average monthly salary for this school's teacher is 21 850 CZK. How many teachers of
  • Parking
    bus_and_car 120 vehicles parking on the morning. Pasenger car is charged 20 CZK, 50 CZK per bus. The guard collected for parking 2640 CZK in total. How many cars and how many buses stood in the parking?
  • Motel
    motorest Three different dinners A, B, C are served in the motel. Three 20 members went to motel. Group 1 ordered dinners: A 20 members and their average dinner price in the group was CZK 200. From Group 2, they ordered a A: 10 persons, B 10 dinners, and their ave
  • Two teas
    tea A mixture weighing 10 kg was made from two types of tea. The price of tea was 160 CZK/kg and second tea 170 CZK/kg. The price of the mixture is 166 CZK/kg. How many kilograms of each type of tea had to be mixed?
  • Eva
    susienky When Eva buys 8 packages of cookies, 4 CZK left her. If she wanted to buy 10 packages, she would have to borrow 20 CZK. How much money has Eva in her wallet?
  • The bookkeeper
    books The bookkeeper bought 45 copies of fairy tale books for CZK 120 and 65 copies of the encyclopedia for CZK 325. then he sold it in his shop like this: fairy tales for 135 CZK and encyclopedias for 360 CZK. What was the purchase price of the books? And the
  • Performance
    theathre Same number of tickets sold for 15 CZK, 20 CZK, 30 CZK and 40 CZK a total of CZK 13,230 on theatre performance. How many tickets were sold for this performance?
  • Tea mixture
    tea Of the two sort of tea at a price of 180 CZK/kg and 240 CZK/kg we make a mixture 12 kg that should be prepared at a price of 200 CZK / kg. How many kilos of each sort of tea will we need to be mixed?
  • Concert
    freddie-mercury On a Concert were sold 150 tickets for CZK 360, 235 tickets for 240 CZK and 412 for 180 CZK. How much was the total revenues for tickets?
  • Three friends
    money Three friends divided the profit 104,650 CZK, so that for every 4 CZK, which got the first friend equals 5 crowns for second and for every 9 CZK, which got the second equals 16 CZK for third. Question: Who got the most and how much.