Sarah has 8 coins worth $1.40. Some of the coins are nickels and some are quarters. a. Let q = the number of quarters and n = the number of nickels. Write an equation relating the number of quarters and nickels to the total number of coins. b. Write an equation relating the value of the quarters and the value of the nickels to the total value of the coins. c. How many of each coin does Sarah have?

a.

b.

c. Sarah has 3 nickels and 5 quarters

Sep-by-step explanation:

Given

Coins = 8

Worth = $1.40

Solving (a): Equation relating to number of coins

From the question, we understand that

q = quarters

n = nickels

The required equation is:

Solving (b): Equation relating to worth of coins

So, the equation is

Solving (c): Values of q and n

Make n the subject of formula in (a)

Substitute 8 - q for n in (b)

Collect Like Terms

Make q the subject of formula

Substitute 5 for q in

Hence;

Sarah has 3 nickels and 5 quarters

i think the correct option is the second option.

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560