A bamboo shoot, from germination to growth, if it grows twice as high every day, it can grow to 40 cm after 10 days. When it grows to 5 cm A bamboo shoot, from germination to growth, if it grows twice as high every day, it can grow to 40 cm in 10 days. How many days does it take to grow to 5 cm? How to calculate?

A bamboo shoot, from germination to growth, if it grows twice as high every day, it can grow to 40 cm after 10 days. When it grows to 5 cm A bamboo shoot, from germination to growth, if it grows twice as high every day, it can grow to 40 cm in 10 days. How many days does it take to grow to 5 cm? How to calculate?

It grows 40 decimeters in 10 days;
9 days long 40 / 2 = 20 decimeters;
8 days long 20 / 2 = 10 decimeters;
10 / 2 = 5 decimeters in 7 days

The utilization rate of a cube wood with an edge length of 40 cm is 1______ ．

The volume of cube is: 40 × 40 × 40 = 64000 (cubic centimeter), the volume of cylinder is: 3.14 × (40 △ 2) 2 × 40, = 3.14 × 400 × 40, = 50240 (cubic centimeter), 50240 △ 64000 × 100% = 78.5%. Answer: the utilization rate of this cube wood is 78.5%. So the answer is: 78.5%