A child's coin bank contains $2.58 in pennies and nickels. If the number of pennies is 36 less than 2 times the number of nickels, how many pennies are in the bank?

A) 38 pennies
B) 42 pennies
C) 48 pennies
D) 2 pennies

let the number of nickels be x

then the number of pennies is (2x - 36)
5x + 2x-36 = 258
7x = 294
x = 42

so 42 nickels and 48 pennies

check: 42(5) = 48 = 258

To solve this problem, we need to set up two equations based on the given information. Let's assume the number of nickels is N and the number of pennies is P.

First, we know that the total value of the coins in the bank is $2.58. Since each penny has a value of $0.01 and each nickel has a value of $0.05, we can write the equation:

0.01P + 0.05N = 2.58 (equation 1)

Second, we're told that the number of pennies is 36 less than 2 times the number of nickels. This can be written as:

P = 2N - 36 (equation 2)

Now, we can solve these two equations simultaneously to find the values of P and N.

Substitute equation 2 into equation 1:

0.01(2N - 36) + 0.05N = 2.58

Simplify and solve for N:

0.02N - 0.36 + 0.05N = 2.58
0.07N = 2.94
N = 2.94 / 0.07
N ≈ 42

Therefore, there are approximately 42 nickels in the bank. Now, we can substitute this value back into equation 2 to find the number of pennies:

P = 2(42) - 36
P = 84 - 36
P = 48

Thus, there are 48 pennies in the bank.

Therefore, the correct answer is C) 48 pennies.