Gerald has 80% more money than his brother, Jerry. If Gerald gives Jerry $72, Jerry will have 80% more than Gerald. How much money do the two brothers have altogether?



Answer :

To solve this problem, let's break it down into steps:

1. Identifying the variables:
- Let's denote the amount of money Gerald has initially as [tex]\( G \)[/tex].
- Let's denote the amount of money Jerry has initially as [tex]\( J \)[/tex].

2. Setting up the first equation:
- We know that Gerald has 80% more money than Jerry. Therefore, [tex]\( G = 1.8J \)[/tex].

3. Setting up the second equation:
- If Gerald gives Jerry [tex]$72, the new amount of money Gerald has will be \( G - 72 \). - The new amount Jerry has will be \( J + 72 \). - According to the problem, after this transaction, Jerry will have 80% more money than Gerald. Therefore, \( J + 72 = 1.8(G - 72) \). 4. Solving the system of equations: - We now have two equations: \[ G = 1.8J \quad \text{(1)} \] \[ J + 72 = 1.8(G - 72) \quad \text{(2)} \] 5. Solve equation (1) for \( G \): \[ G = 1.8J \] 6. Substitute \( G \) in equation (2): \[ J + 72 = 1.8(1.8J - 72) \] 7. Expand and simplify: \[ J + 72 = 1.8 \cdot 1.8J - 1.8 \cdot 72 \] \[ J + 72 = 3.24J - 129.6 \] \[ 72 + 129.6 = 3.24J - J \] \[ 201.6 = 2.24J \] \[ J = \frac{201.6}{2.24} \] \[ J = 90 \] 8. Now find \( G \): \[ G = 1.8J \] \[ G = 1.8 \times 90 \] \[ G = 162 \] 9. Calculate the total amount of money the two brothers have altogether: \[ \text{Total money} = G + J \] \[ \text{Total money} = 162 + 90 \] \[ \text{Total money} = 252 \] Therefore, Gerald and Jerry together have $[/tex]252 initially.