Accelerated Algebra II
Section 5.8 day 2
Goal: To solve word problems having equations with fractional coefficients.
Solve.
1. 12 is
3
10
of
of a number. Find the number.
5
21
2. 75% of 60% of the number is 36. Find the number.
Work Rate:__________________________________________________________________________
1
 If you can mow a lawn in 2 h, your work rate is job per hour.
2

If you can type a paper in 4 hours, your work rate is ____________per hour.

If you can clean your room in 30 min, your work rate is _________per minute.

A whole job is done when the sum of the fractional parts is 1.
Solve. (hint: create a chart)
3. Ted can paint a wall in 20 min. Vern can paint the same wall in 30 min. How long would it take them
to paint the wall working together?
4. A file clerk needs 6 hours to file an average day’s paperwork. It takes a trainee 12 hours to do the
same job. How long will it take if they work together?
5. How much water must be evaporated from a 300 L tank of a 2% salt solution to obtain a 5% solution?
6. How many liters of pure acid should be added to 4 L of a 10% acid solution to make a solution that is
80% acid?
7. How much of an 18% solution of sulfuric acid should be added to 360 mL of a 10% solution to obtain
a 15% solution?
1
% interest. The money earned from
4
the interest is $2,250. Find out how much was invested at each rate.
8. Daniel invested $21,000, part at 12% interest and the rest at 5
9. Lina invested $24,000, part at 8% and the rest at 7.2%. How much did she invest at each rate if her
income from the 8% investment is two thirds that of the 7.2% investment?
Homework: Solve. Set up a chart to help with work rate/solution/investment problems.
1.
5
4
of of a number is 15. Find the number.
16
5
2. 30 is 20% of 30% of the number. Find the number.
3. Pump A can unload the Lunar Petro in 30 h and pump B can unload it in 24 h. Because of the storm
approaching, both pumps were used. How long did they take to empty the ship working together?
4. How much pure antifreeze must be added to 12 L of a 40% solution of antifreeze to obtain a 60%
solution?
5. How many liters of water must be evaporated from 10 L of a 40% salt solution to produce a 50%
solution?
6. How much of an 8% saline solution should be added to 600 mL of a 3% solution to produce a 5%
solution?
Answers:
1. 60
2. 500
4. 6 L
5. 2 L
1
3. 13 hr or 13 hr 20 min
3
6. 400 mL