Question

Compact fluorescent lamps (CFLs) consume one-fourth of electricity than consumed by incandescent
bulbs and CFLs last eight times longer than incandescent bulbs. If the electricity consumed by a household
using incandescent bulbs is 820 units at the rate of ₹4.50 per unit, then answer the following questions
(MCQs – multiple choice questions):-
a) How many units of electricity will be consumed if all bulbs are changed to CFLs?
i. 840 units
ii. 120 units
iii. 210 units
iv. 205 units
b) The amount to be paid when incandescent bulbs are used is
i. ₹4.50
ii. ₹3690
iii. ₹36900
iv. ₹369
c) What is the ratio of units consumed when incandescent bulbs are used to units consumed when CFLs
are used?
i. 160 : 81
ii. 81 : 160
iii. 1 : 4
iv. 4 : 1​

Answer 1

Answer:

a) iii

b) ii

c) iv

Step-by-step explanation:

a)

As CFL'S consume one-fourth of current than incandescent bulbs then

820/4=210

b)

For 1 unit it costs 4.5 rupees

then for 820 units

820*4.5=3690 rupees.

c)

(Units consumed by incandescent bulbs) /(Units consumed by CFL'S)=

820/210=4:1