Explanation:
2 bakers make 30 loaves in 1 hour.
that means each baker just by him-/herself can make 15 loaves in 1 hour.
so,
1 baker's "speed" = 15 loaves/hr
15 l/h = 30l/x
x = 30/15 = 2 hours (1 baker takes 2 hours to make 30).
3 bakers' speed = 3×15/hr = 45l/h
45l/h = 30l/x
x = 30/45 = 2/3 hours (3 bakers need 2/3 hours = 40 minutes to make 30 loaves).
5 bakers = 5×15l/h = 75 l/h.
75l/h = 30l/x
x = 30/75 = 2/5 hours (5 bakers need 2/5 hours = 2×60/5 = 24 minutes to make 30 loaves).
6 bakers = 6×15l/h = 90 l/h.
90 l/h = 30/x
x = 30/90 = 1/3 hours (6 bakers need 1/3 hour = 60/3 = 20 minutes to make 30 loaves).
15 bakers = 15×15 l/h = 225 l/h
225 l/h = 30/x
x = 30/225 = 2/15 hours (15 bakers need 2/15 hours = 2×60/15 = 2×4 = 8 minutes to make 30 loaves).