Some rates are constant whereas others vary with time. For example, we know the speed of a car varies as we accelerate or brake.
If a rate remains constant over time then we can use this to solve problems.
Problem 1 :
Water consumption for a person living in Sydney is approximately 2100 liters per week. At this time, how much water would be used by a person in two days ?
Solution :
Water consumption per week = 2100 liters
Water consumption per day = 2100/7
= 300
Water used in one day = 300(2)
= 600 liters
Problem 2 :
Bill is a part time curator at the local cricket ground. He earned $169.60 for working 8 hours last week. This week he has worked 21 hours. How much will he earn this week if he is paid at the same hourly rate?
Solution :
His earning for 8 hours = 169.60
His earning in 1 hour = 169.60/8
= 21.2
His earning for 21 hours = 21 (21.2)
= 445.2
Problem 3 :
A petrol tanker takes 18 minutes to discharge 8100 liters of fuel.
a) At this rate, how much fuel would the tanker discharge in 14 minutes ?
b) How long would it take the tanker to discharge 4950 litters of fuel at the same rate?
Solution :
Time taken to discharge 8100 liters of fuel = 18 minutes
So, in 1 minute it will discharge = 8100/18 liters
= 450 liters
Problem 4 :
A motor vehicle can travel 84 km on 7 liters of petrol.
a) How far could the vehicle travel on 57 liters of petrol?
b) How many liters of petrol would be required to travel a distance of 420 km?
Solution :
Distance covered using 7 liter of petrol = 84 km
Distance covered using 1 liter of petrol = 84/7
= 12 km
Let x be the required quantity of petrol to be used to cover the distance of 420 km.
x = 420/12
x = 35
So, required quantity of petrol to cover 420 km is 35 l.
Problem 5 :
It costs $2340 to lay a drain pipe of length 36 m.
a) Find the cost of laying a drain pipe of length 63 m.
b) Find the length of pipe that could be laid for a cost of $7540.
Solution :
Cost spent to lay drain pipe of length 36 m = 2340
Cost spent to lay drain pipe of length 1 m = 2340/36
= 65
Cost spent for laying a drain pipe of length 63 m
= 65(63)
= $4095
Let x be the required length of pipe that could laid for the given cost
x = 7540/65
x = 116
So, required quantity of pipe is 116 m.
Kindly mail your feedback to v4formath@gmail.com
We always appreciate your feedback.
©All rights reserved. onlinemath4all.com
Aug 06, 22 11:56 PM
Aug 06, 22 11:31 PM
Aug 06, 22 09:01 AM