Banknotes

Eva deposit 7800 USD in 50 banknotes in the bank.
They had a value of 100 USD and 200 USD.
How many were they?

Correct answer:

a =  22
b =  28

Step-by-step explanation:


a+b = 50
100a+200b = 7800

a+b = 50
100•a+200•b = 7800

a+b = 50
100a+200b = 7800

a = 22
b = 28

Our linear equations calculator calculates it.



We will be pleased if You send us any improvements to this math problem. Thank you!






avatar




Tips to related online calculators
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?

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

Related math problems and questions:

  • Salary
    500euro Lawyer got to pay 840 Euros in banknotes of 20 and 50 Eur. Total got 18 banknotes. How many was which?
  • Simple interest
    bank Peter put into bank 853 euros deposit. After 7 years on account overall was 984 euro. What was the interest rate if bank add simple interest?
  • Cranberries
    vaha_22 They brought 65 kg of dried cranberries to the packing house. They made 150-gram and 200-gram packages from them. How many kilograms of cranberries did they use for the smaller 200 packages? How many 200 gram packages were there?
  • Two accounts
    bankovka Two accounts in the bank, one per year interest 2%, the second 3%. Total interest income 1900 USD. If interest rates were reversed, the yield would be USD 200 higher. What are the amounts on each account?
  • Pennies
    Toliar.preview 800 pennies have the same value as 100 ducats. 100 pennies have the same value as 250 tolars. How many ducats has the same value as 100 tolars?
  • Banknotes
    penize How many different ways can the cashier payout € 310 if he uses only 50 and 20 euro banknotes? Find all solutions.
  • Exchange € 100
    penize_3 Find out how many ways you can exchange € 100 if you have an unlimited number of 50, 20, 10 and 5 euro banknotes. Use a method other than listing all options systematically.
  • Dollars
    children Mama split 760 dollars Jane, Dane and Eva as follows: Jane got three times more than Dane and Dane and got 40 more than Eva. How much does get each of them?
  • Euros
    bicycles Peter, Jane, and Thomas have together € 550. Tomas has 20 euros more than Jane, Peter € 150 less than Thomas. Determine how much has each of them.
  • 925 USD
    money_22 Four classmates saved an annual total 925 USD. The second save twice as the first, third 35 USD more than the second and fourth 10 USD less than the first. How USD save each of them?
  • Bank deposit
    bank_1 Ms Jana after the withdraw amount of 2,500 euros after year saving in bank. What was her deposit if the interest rate was 2.5% p.a..
  • Salary
    kcs Mr. Johnson's had monthly salary 955 USD since the beginning of year. From which month his salary was increased by 52 USD, when in year earned 11824 USD (enter as a number from 1 to 12)?
  • Boys and money
    money_12 270 USD boys divided so that Peter got three times more than Paul and Ivan has 120 USD more than than Paul. How much each received?
  • Saving
    2kc Paul saves 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins?
  • Price reduction
    camera The price of the camera is 654 USD on sale. They reduced its price to 411 USD. Calculate the percentage reduction in the price of the camera.
  • Mr. Brown
    bank_1 Mr. Brown invested 15,000 euros in the bank for an annual term deposit. After the first year, he gained 600 euros. What was the annual interest rate of his deposit?
  • Annual income
    income The annual income (in thousands of $) of fifteen families is 60, 80, 90, 96, 120, 150, 200, 360, 480, 520, 1060, 1200, 1450, 2500, 7200. Calculate the harmonic and geometric mean.