Answer:
Number of left-handed students in his school s
46
Explanation:
As Tom has 10 out of every 85 students in his school as left-handed, this is equivalent to
10/85 = 2*5/17*5 = 2/17
i.e. 2 out of every 17 students in his school are left-handed.
Hence out of 391 students, number of left-handed students are
391 ×2/17= 23 × 17 ×2/17 =23 × (17) ×2/1(17) = 23 ×2 = 46
note whatever is in() is crossed out or cancelled out by another