Answer Happy

Yearly Budget:
Bajaj has invested in solar operated lamps. Each lamp has two
units: one bulb (to
be fixed inside the house) and a solar battery (to be fixed
outside). These two units
are connected by electrical wire and a switch. Average life of the
battery is two
years, and that of the bulb is six months. The solar battery, and
the bulb can be
bought separately (as replacements).
(a) On April 1 (next year) you will fix one such solar operated
lamp in your house.
Determine the minimum number of lamps you will buy (as
replacements) so
that you are at least 99% sure of meeting your requirement of lamp
in the next
financial year.
(b) Suppose on April 1 (next year) 400 households will fix one such
solar operated
lamp in each household. Determine the minimum number of
replacements of
bulbs B that will meet total replacements of these 400 households
with at least
99% chance during the next financial year.
(c) For these 400 households, it is needed to allocate both bulbs
as well as battery
sets to meet requirements of replacement during the next financial
year. A bulb
costs Rupees 500, and a battery costs Rupees 8000. Determine the
minimum
budget F that will be sufficient for the next financial year with
at least 99%
chance. (This common budget is for replacements of bulbs, as well
as battery
sets.)