In a certain code, 'HELLO' is written as '8-5-12-12-15'. How is 'WORLD' coded in the same system?

A. 23-15-18-12-4

How many times does the letter 'A' appear in the series: A, B, A, C, A, D, E?

B. 3

If '?' represents division and '?' represents addition, what is the result of 20 ? 4 ? 6?

C. 8

In a coded relation, if M - N means M is the sister of N, M × N means M is the daughter of N, and M + N means M is the mother of N, what is the relationship of O if M - N + O?

B. O IS M'S DAUGHTER

If '?' represents multiplication, '?' represents division, '?' represents addition, and '?' represents subtraction, what is the value of 10 ? 2 ? 5 ? 5?

A. 20