Need Help On 5th Grade Word Problems

Question

1) A tank 60 cm long, 40 cm wide and 20 cm high is half-filled with water. If all the water is poured into an empty fish tank with a rectangular base measuring 48 cm by 25 cm, find the depth of the water in the fish tank.

2) Tank A, measuring 20 cm by 30 cm by 10 cm, is full of water. Tank B, measuring 30 cm by 50 cm by 10  cm is 2/3 full of water. Find the difference in the amount of water in the two tanks. Give your answer in liters. (1 liter = 1,000 cm cubed)

3) 9 liters of cooking oil are poured into rectangular containers, filling each up to a height of 30 cm. The base of each container measures 5 cm by 3 cm. How many containers are needed? (1 liter = 1,000 cm cubed)

4) A cubic tank of side 36 cm is half-filled with water. How much will the water level rise when a metal block of volume 5184 cm cubed is placed in the tank?

Answer 1

1) Volume of water=60*40*10=24000cc because the tank is only half full, so depth of water is 10cm.

Surface area of base of fish tank=48*25=1200sq cm. so the depth of the water in the fish tank=24000/1200=20cm.

2) Volume of Tank A=20*30*10=6000cc=6L. Volume of water in Tank B=⅔*30*50*10=10000cc=10L. Difference is 4L.

3) Volume of oil=3*5*30=450cc in container. 9L=9000cc. Number of containers=9000/450=20.

4) Volume of water in tank is 36*36*18=23328cc. Add 5184cc=28512cc. To find new height of water, we divide by the base area: 28512/36²=22cm. So water level rises from 18 to 22 cm, that is, 4cm. Another way to solve this is to divide the added volume by the base area: 5184/36²=5184/1296=4cm.