A 60-Watt bulb illuminates a surface a distance d away with
an illuminance of 3600 lux. What would be the illuminance
on a surface a distance 0.5•d away (i. e., one-half the
distance away) when illuminated by a 120-Watt bulb?

Explanation:

Relation between power and illumination and distance  is as follows

For first  case

for second case

I = 3600 x 8

= 28800 lux .

emily ruth's annual premium is $1058.50

step-by-step explanation:

emily ruth is a female of 27 years age purchasing 20 year endowment insurance with face value $25000.

from the given table,

for females, the age of a male 3 years younger should be used.

so, we have to check for 24 year male for 20 year endowment.

it is 42.34 for every $1000 face value.

for a face value of $25000,

it is 25 * 42.34 = $1058.50

∴ emily ruth's annual premium is $1058.50

50 inches should be the resultant vector