It turns out that 5% of 400 is 20.
(1/20)*400=20.
So Ian was being paid £400 a week before he was given a pay rise.
there are 60 minutes per hour
99/60 = 1.65 km per minute
1.65 x 2 = 3.3 km in 2 minutes
Ab+ac=a(b+c) where a is the greatest common factor
find greatest common factor of 10 and 50
10=1,2,5,10
50=1,2,5,10,25,50
greatest common is 10
a=10
10(1)+10(5)=10(1+5)=10(6)=60