Alan travels 3/10 of his journey car. 3/20 by bicycle 1/12 by boat and walks the rest what fraction of the journey did he walk? If the journey is 140 km, how many km did he walk?

The denominators are: 10, 20, and 12

The LCD (lowest common denominator) is 60 as this is the smallest multiple of 10, 20, and 12.

Get each fraction to have a denominator of 60

3/10 = (3/10) * (6/6) = (3*6) / (10*6) = 18/60

3/20 = (3/20) * (3/3) = (3*3) / (20*3) = 9/60

1/12 = (1/12) * (5/5) = (1*5) / (12*5) = 5/60

The fractions

3/10, 3/20, and 1/12

are equivalent to

18/60, 9/60, and 5/60

in that exact order

Add up the second set of fractions to get

(18/60) + (9/60) + (5/60) = (18+9+5) / 60 = 32/60 = 8/15

The result of adding the fractions and reducing leads to 8/15 meaning that Alan takes 8/15 of the journey to use his car, bike and boat

The rest of the journey (7/15) is done walking

Multiply this with the total distance 140

(7/15) * 140 = (7/15) * (140/1)

(7/15) * 140 = (7*140) / (15*1)

(7/15) * 140 = (980) / (15)

(7/15) * 140 = (975+5) / 15

(7/15) * 140 = (975/15) + (5/15)

(7/15) * 140 = (65) + (1/3)

(7/15) * 140 = 65 & 1/3

The answer as a mixed number is 65 & 1/3

The answer as an improper fraction is 980/15

The approximate answer in decimal form is 65.33 (rounded to 2 decimal places)