Question

Question 5 (ii)
The following table gives the life times of neon lamps:
$\begin{array}{cc}\text{Length (in hours)}& \text{Number of lamps}\\ 300-400& 14\\ 400-500& 56\\ 500-600& 60\\ 600-700& 86\\ 700-800& 74\\ 800-900& 62\\ 900-1000& 48\end{array}$
(ii) How many lamps have a life time of more than 700 hours?

Answer 1

(ii) It can be concluded that the number of neon lamps having their life time more than 700 is the sum of the number of neon lamps having their life time as 700−800, 800 − 900, and 900−1000.
Therefore, the number of neon lamps having their life time more than 700 hours is 184. (74 + 62+48 = 184)