# Ray

Light ray loses 1/19 of brightness passing through glass plate. What is the brightness of the ray after passing through 7 identical plates?

x =  0.617

### Step-by-step explanation:

$x=1\cdot \left(1-\frac{1}{15}{\right)}^{7}=0.617=61.7\mathrm{%}$ Did you find an error or inaccuracy? Feel free to write us. Thank you! Tips to related online calculators
Need help to calculate sum, simplify or multiply fractions? Try our fraction calculator.

## Related math problems and questions:

• Wire One pull of wire is reduced its diameter by 14%. What will be the diameter of wire with diameter 19 mm over 10 pulls?
• 6 plates 6 plates and 5 cups cost 37.50 dollars. 7 plates and 6 cups 44.10 dollars. Each plate costs the same amount as the other cup. What is the cost of 1 plate? What is the cost of 1 cup? The glass of 1 mm thickness absorb 4% of UV radiation passing through. How many percent of UV rays absorb glass with a thickness 1.1 cm, made from 1 mm thick those glasses?
• Sequence 11 What is the nth term of this sequence 1, 1/2, 1/3, 1/4, 1/5?
• Gp - 80 One of the first four members of a geometric progression is 80. Find its if we know that the fourth member is nine times greater than the second.
• Deposit If you deposit 719 euros at the beginning of each year, how much money we have at 1.3% (compound) interest after 9 years?
• Refractive index The light passes through the interface between air and glass with a refractive index of 1.5. Find: (a) the angle of refraction if light strikes the interface from the air at an angle of 40°. (b) the angle of refraction when light strikes the glass interfa
• Quotient Determine the quotient and the second member of the geometric progression where a3=10, a1+a2=-1,6 a1-a2=2,4.
• Insert 6 Insert four harmonic means between 3/7 and 3/19
• Find the 19 Find the 1st term of the GP ___, -6, 18, -54.
• Mean if the mean of the set of data 5, 17, 19, 14, 15, 17, 7, 11, 16, 19, 5, 5, 10, 8, 13, 14, 4, 2, 17, 11, x is -91.74, what is the value of x?
• Profitable bank deposit 2012 Calculate the value of what money lose creditor with a deposit € 9500 for 4 years if the entire duration is interest 2.6% p.a. and tax on interest is 19%. Annual inflation is 3.7% (Calculate what you will lose if you leave money lying idle at negative int
• Discount Product has been discounted twice by 19%. What is the total discount given? A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years? Apply for a \$ 59000 loan, the loan repayment period is 8 years, the interest rate 7%. How much should I pay for every month (or every year if paid yearly). Example is for practise geometric progression and/or periodic payment for an annuity. The sum of three numbers in GP (geometric progression) is 21 and the sum of their squares is 189. Find the numbers. In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is sn≤217.