In a study, the sample is chosen by writing everyone's name on a playing card, shuffling the deck, then choosing the top 20 cards What is the sampling method?
a. Simple
b. Random
c. Systematic
d. Stratified
e. Cluster
f. Convenience

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

he made 11 calls in one day

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27