We use the multiples of 9 and 15. 9:9,18,27,36,45,54,63,73,81,90,99,108,117,126,135 15:15,30,45,60,75,90,105,120,135 The first common multiple in this case it is 135 is the answer as they asked in how many secnds the two neon lights blink together again
(a) (i) In first 4 minutes Mary's speed was 600 / 4 = 150 m / minute (ii) in last 4 minutes her speed was (1000-600) / 4 = 400/4 = 100 m/min (b) Marys average speed for the whole journey = 1000/8 = 125 m/min (c) 200 m (d) Peter arrived at school after 7 minutes . Mary took 8 minutes. Peter first. (e) Where they met is given by where the 2 curves intersect. That is at time 6.8 minutes and 880 m from Mary's home (f) At t= 4 dsitance between then is 600 - 400 = 200 m
Well the angles should all equal 360. Since you know 90 and 160 then 360-90-160=110. Angle 2 is 90* so 110-90=20 so angle 4 is 20. Angle 2+ angle 4: 90+20=110 or C :)
