[ratio and proportion word problems][section
50]
(1.) A train travelled 90 miles in 1.5
hours. How many miles
will it travel in 6 hours going at
the same rate of speed?
90/1.5 = x/6 here is the problem
1.5x = 540 cross multiply
____
____
1.5
1.5 divide each side by
1.5
x
= 360 divide and cancel
result: 360 miles
(2.) Fifty feet of copper wire weighs 2
pounds. How much will
325 feet of the same wire weigh?
50/2 = 325/x here is the problem
50x = 650 cross multiply
____ ____
50 50
divide each side by 50
x = 13 divide and cancel
result: 13 pounds
(3.) A recipe for a two-pound cake calls
for 1.5 cups of
butter. How many cups of butter will be needed for
a five-pound cake?
2/1.5 = 5/x here is the problem
2x = 7.5 cross multiply
___ _____
2 2
divide each side by 2
x = 3.75 divide and cancel
result: 3.75 cups of butter
(4.) 0.7 cm of rain fell in 3
hours. How many cm of rain
will fall in 9 hours at the same
rate?
0.7/3 = x/9 here is the problem
3x = 6.3 cross multiply
____ ____
3 3
divide each side by 3
x = 2.1 divide and cancel
result: 2.1 cm of rain
(5.) 1.5 cm represents 60 km. What distance does 6 cm
represent?
1.5/60 = 6/x here is the problem
1.5x = 360 cross multiply
____ _____
1.5 1.5
divide each side by 1.5
x = 240 divide and cancel
result: 240 km
(6.) 5 pounds of meat makes 22 meat
patties. How many
patties of the same size can be
made from 17.5 pounds
of meat?
5/22 = 17.5/x here is the problem
5x = 385 cross multiply
___ ____
5 5
divide each side by 5
x = 77 divide and cancel
result: 77 patties
(7.) Wallpaper to cover 55 square feet
costs $16. How much
will it cost to cover 330 square feet?
55/16 = 330/x here is the problem
55x = 5280 cross multiply
_____ ____
55 55 divide each side by 55
x = 96 divide and cancel
result: $96
(8.) A nurse checking the heartbeat of
a patient counted 19
beats in 15 seconds. What was the patients heartbeat
for 60 seconds?
19/15 = x/60 here is the problem
15x = 1140 cross multiply
____ _____
15 15
divide each side by 15
x = 76 divide and cancel
result: 76 beats per minute
(9.) A car travels 110 km in 3 hrs. How far will it travel
in 5 hrs at the same rate of speed?
110/3 = x/5 here is the problem
3x = 550 cross multiply
___ ____
3 3
divide each side by 3
x = 183 1/3 divide and cancel
result: 183 1/3 km
(10.) A printing press runs 500 copies
of a brochure in 8
minutes. How long will it take to run 200,000 copies
at the same rate?
500/8 = 200,000/x here is the problem
500x = 1,600,000 cross multiply
______ ___________
500 500
divide each side by 500
x = 3200 divide and cancel
result: 3200 minutes