The average value of three consecutive natural numbers is 20, and these three numbers are (19), (20) and (2 1) respectively.

The heights of a group of six students are 144cm, 150cm, 140cm, 139cm, 145cm, 152cm respectively, and the average height of these six students is (152cm.

In a/5 (a is not 0), when a (>; 5), this score is a true score; When a (

The area of a rectangular piece of paper is the original (1/8) after three alignments (completely overlapping after folding).

12kg is 20% less than (10) kg.

The clock turned from 9 o'clock to 12 o'clock, and the hour hand turned (90) degrees.

A cuboid container holds 48 liters of water, which is just full. When an iron block is immersed in water, the water overflows 65,438+08 liters. The volume of this iron block is (5)/(8) less than that of the cuboid container, which is (62.5)% less.