Bob has 18 coins, both dimes and nickels, worth $1.45. How many of each coin does he have?

Dimes: 11 , Nickels: 7

Step-by-step explanation:

Let's say the number of dimes ⇒ x and the number of nickels ⇒ y:

We know the total number of coins, 18 , such that we can format one equation to be:

x + y = 18

We also know the total cost of dimes and nickels, 1.45 dollars. Here we (in general) know that the cost of a dime is 0.1 dollars and the cost of a nickel is 0.05 dollars so that 0.1x represents the total cost of dimes if x represents any number, and 0.05y represents the total cost of nickels if y represents any number. Knowing this, let us format another equation to be:

0.1x + 0.05y = 1.45

So, we now have two equations:

x + y = 18, and

0.1x + 0.05y = 1.45

Let's alter the first equation as such, so that x is isolated:

x + y = 18

x = 18 - y

Now let's substitute the this value of x in the second equation and solve for y:

0.1x + 0.05y = 1.45

0.1(18 - y) + 0.05y = 1.45

1.8 - 0.1y + 0.05y = 1.45

1.8 - 0.05y = 1.45

-0.05y = -0.35

y = 7 nickels

Knowing the number of nickels, substitute the value of y into the first equation:

x + y = 18

x + (7) = 18

x = 11 dimes

more detail

step-by-step explanation:

answer: a. 13/44

step-by-step explanation: judging by the information given to us, we are looking for experimental probability. we can see that 13 males have chosen chocolate ice cream. there are 44 ice creams in total (remember that the total is always the denominator). so our answer is 13/44.