χ+2χ+ 17=38
3χ+ 17=38
3χ=38- 17
3χ=2 1
χ=7
Today's era seeks a:
〔 1 13-7×2-( 17+7)〕÷3
=75÷3
= 25 years old
Now the era of seeking B:
25+7 = 32 years old
A: B is 32 years old now.
Solution 2, use arithmetic to solve:
According to the second condition, "When B is half the age of C, A is 17 years old", in the first condition, the age difference between B and A can be regarded as 1 unit, and the age difference between C and B is 1 unit plus 17 years old. According to the quantitative relationship provided by the first condition, we can know that the age of C 38 is the sum of the three B A age differences 17. In this way, the age difference between B and A can be found, that is, (38- 17) ÷ 3 = 7 (years old).
The age difference between C and B is 17+7 = 24 (years).
B's age is (113-7× 2-24) ÷ 3+7 = 75 ÷ 3+7 = 32 (years).