Elio is right in assuming the relationship between the height and the hours it burns is proportional.
Find the unit rate
14 ÷ 8 = 1.75 cm/h
Divide
21 ÷ 1.75 = 12
You can set this up as an algebraic equation to check the answer.
If the candle is 21 cm tall, it will burn for 12 hours.
Hope this helped you! :)
Just subtract but take care of the power or else you can come up with wrong results !
so first make the power same ;
for Jupiter = 1.898× 10(27) = 18.98 × 10(26)
for Saturn = 5.68×10(26)
so now subtract = (18.98-5.68) × 10(26)
= 13.3 × 10(26)
so the answer is 13.3 ×10(26)
or, 1.33× 10(27)
let h be the number of hours then
A → C = 150h + 250 ( where C is charge )
B → C = 175h + 150
for 26 hours
A → C = (150 × 26 ) + 250 = 3900 + 250 = $4150
B → C = (175 × 26 ) + 150 = 4550 + 150 = $4700
Attorney A is cheaper for 26 hours, thus better deal
Equate the 2 equations to find hours they charge the same
175h + 150 = 150h + 250 ( subtract 150h from both sides )
25h + 150 = 250 ( subtract 150 from both sides )
25h = 100 ( divide both sides by 25 )
h = 4 ← number of hours when charges for both are equal
Thus Attorney A becomes a better deal at 5 hours
3/4 - 1/5
0.75 - 0.2
0.55
Answer: 0.55 or 11/20