Maths Problem Solving

1. Kit and May each have some money. If Kit spends $80, the ratio of the amount of money Kit has to the amount that May has will become 4:7. If May spends $80, the ratio will become 6:5. How much money do the girls have altogether? (5m)

2. There is 40% more water in Tank A than in Tank B. If I transfer 45 ml of water from Tank A to Tank B, Tank B will have 25% more water than
Tank A. What is the total amount of water in Tank A and Tank B? (5m)

3. If Jeff adds 1 to the numerator of a fraction, the fraction becomes one
whole. If he adds 4 to the denominator, the fraction becomes 1/2. What is the fraction? (3m)

4. I run 1600 m at the NAPFA Test. If I run 400 m and walk 1200 m, I
will take 30 minute. If I run 800 m and walk 800 m, I will need 6 minute less. How long will I take to complete the run if I run all 1600 m? (4m)

5. Donald usually drives at 90 km/h from his home to his office. Last Friday, he decreased his speed by 30 km/h and arrived at his office 10 minutes later. What is the distance between his house and his office? (4m)

6. Paul and Tim began a race together. When Paul finished the race in 30 min, Tim was only 4/7 through the race. If Paul ran 6 km/h faster than Tim, what was Tim's speed in km/h? (4m)

7. Chris has 480 more stamps than Dill. If Dill gives Chris 20 stamps, Chris will have 40% more stamps than Dill. How many stamps does Chris have? (4m)