80% of 100 multiplied by 60% of 300 gives :
14400
2880
18800
28500
80% of 100 = 80100×100 = 80
60% of 300 = 60100×300 = 180
80 × 180 = 14400
Life (in Hrs.)
0-20
20-40
40-60
60-80
80-100
100-120
No. of electric bulbs
31
36
38
42
82
71