Assemble the troops, let the soldiers 1, 2, 3- 1, 2, 3, 4, 5- 1, 2, 3, 4, 5, 6, 7 report the number of three, and report each remainder, and you will know that the actual number of troops is missing from several calculation histories. It's called ghost valley calculation, also called residue theorem. The solution to the problem is summed up in a poem: three peers are seventy sparse, five trees, twenty branches and seven reunions, and the meaning is known by dividing by one hundred and a half. The first remainder is multiplied by 70, the second by 2 1, the third by 15, and the remainder is added and divided by 1 to get the number.
1×70+2×2 1+3× 15= 157
157÷ 105= 1……52