Question

A pile of 55 coins, consisting of nickels and dimes, is worth $3.90. find the number of each.

Answer 1

N + D = 55 coins (1) (N stands for nickels, 5N + 10D = 390 cents (2) D stands for dimes) Simplify (2) by canceling the factor 5 in both sides: N + 2D = 78 (3) Subtract eq(1) from eq(3). You will get D = 78 - 55 = 23. Answer. 23 dimes and 55-23 = 32 nickels. Check. 23*10 + 32*5 = 390 cent

Answer 2

N + D = 55 coins (1) (N stands for nickels, 5N + 10D = 390 cents (2) D stands for dimes) Simplify (2) by canceling the factor 5 in both sides: N + 2D = 78 (3) Subtract eq(1) from eq(3). You will get D = 78 - 55 = 23. Answer. 23 dimes and 55-23 = 32 nickels. Check. 23*10 + 32*5 = 390 cents