Question

A bag contains 40 coins, all of them are either 2 cent or 5 cent coins. If the value of the money in the bag is $1.55, find the number of each kind*.
*Use a simultaneous equation to find the number of each.

Answer 1

Answer: Explanation:First, let's call the number of 2 cent coins: tNext, let's call the number of 5 cent coins: fWe can then write to equations from the information in the problem.Equation 1: t+f=40Equation 2: 0.02t+0.05f=1.55Step 1) Solve the first equation for t:t+f=40t+f−f=40−ft+0=40−ft=40−fStep 2) Substitute (40−f) for t in the second equation and solve for f:0.02t+0.05f=1.55 becomes:0.02(40−f)+0.05f=1.55(0.02×40)−(0.02×f)+0.05f=1.550.80−0.02f+0.05f=1.550.80+(−0.02+0.05)f=1.550.80+0.03f=1.550.80−0.80+0.03f=1.55−0.800+0.03f=0.750.03f=0.750.03f0.03=0.750.030.03f0.03=25f=25Step 3) Substitute 25 for f in the solution to the first equation at the end of Step 1 and calculate t:t=40−f becomes:t=40−25t=15The Solution Is:There are:15 two cent coins25 five cent coins

Step-by-step explanation: