Answer:
Inside the jar there's 16 nickels and 35 quarters.
Explanation:
Since there are only nickels and quarters in the jar, the sum of the number of nickels and the number of quarters inside it must be equal to the total number of coins in the jar. So
nickels + quarters = 51
We know the total value inside the jar, to obtain this value we must multiply the amount of each kind of coin by it's value and sum it. So we have:
0.05*nickels + 0.25*quarters = 9.55
We now have two equations and two variables, so we can solve them as follows:
nickels + quarters = 51
0.05*nickels + 0.25*quarters = 9.55
From the first equation:
nickels = 51 - quarters
0.05*(51 - quarters) + 0.25*quarters = 9.55
2.55 - 0.05*quarters + 0.25*quarters = 9.55
0.2*quarters = 9.55 - 2.55
quarters = 7/0.2 = 35
nickels = 51 - 35 = 16
Inside the jar there's 16 nickels and 35 quarters.