Practice Problems: Linear Equations
1. A quarter weighs the same as two pennies. The quarters in one pound of
quarters have a total value of $25. How many dollars would a pound of
pennies be worth?
2. Right now, my sister is three times as old as I am. In 7 years, she will be
twice as old as I will be. How old am I?
3. I invest a total of $13000 in two separate bank accounts, one of which pays
7% simple interest and the other 9%. If I get a total of $1102 in interest
after one year, how much did I place in each account?
4. Mark is 6 years old. His mother is 24 years older than he. In how many
years will Mark’s mother be four times as old as he?
5. A farmer has a total of 750 chickens and ducks. He sold half of the ducks
and bought another 90 chickens. After which, the number of chickens he
had was 1/3 the number of ducks. How many chickens did he have at first?
6. Jack and Jill bring a total of $80 to a store. Jack spends $20 and Jill spends
$24. At the end of the day, Jill has twice as much money as Jack. How much
money did Jill start with?
7. Find the ratio
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in the equations below: (Big Challenge: find all
that
8. At Harold’s Fast Food Restaurant, two hamburgers, three cans of sodas, and
five hot dogs cost $17.80 in total (without tax). At the same restaurant, five
hamburgers, six cans of soda, and nine hot dogs cost $36.00 in total,
without tax. How much more does a hamburger cost than a hot dog at
Harold’s Fast Food Restaurant?