# 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?

### Correct answer:

Tips to related online calculators

Need help to calculate sum, simplify or multiply fractions? Try our fraction calculator.

#### You need to know the following knowledge to solve this word math problem:

## 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? - UV radiation

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? - Radioactive material

A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years? - Loan

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. - Three members GP

The sum of three numbers in GP (geometric progression) is 21 and the sum of their squares is 189. Find the numbers. - Geometric progression

In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is sn≤217.