Answer:
a) 8
b) 2 1/4 hours
c) 4 7/8 hours
d) 4 1/8 hours
Explanation:
a) LCD to be used to solve this problem is calculated as the Lowest common denominator of the above mixed fractions.
We have 1 1/2 hours and 1 1/8 hours
The lowest common denominator is the denominator calculated by
Multiplying the two denominators together and dividing by the common factor of the two denominators
Hence , we have
2 × 8 = 16
The common factor of 2 and 8 = 2
LCD = 16/2 = 8
b) How long did Matt drive?
We are told that Matt drove twice as long as John
John drove for 1 1/8 hours
Hence, the number of hours that Matt drove for =2 × 1 1/8
= 2 × 9/8 = 9/4 hours = 2 1/4 hours
c) How long the Sam, John and Matt drive ?
We are told in the question that
Sam drove for 1 1/2 hours
John drove for 1 1/8 hours
Matt drove for 2 1/4 hours
We would sum up the number of hours that each of them drove.
1 1/2 + 1 1/8 + 2 1/4
The Lowest common multiple of denominators is 8
= (1 + 1 + 2)( 4 + 1 +2/8)
= 4(7/8)
= 4 7/8 hours
d) How many hours is left for Bob to drive
We are told that the entire journey = 9 hours
The number of hours Sam, John and Matt drove for has been calculated in question c as 4 7/8 hours
The number of hours Bob will drive for is calculated as
9 hours - 4 7/8 hours
= 4 1/8 hours