<h3>
Answer: Rs 25</h3>
Explanation:
Each pencil has a profit of Rs 1.25 since 
Multiply that result with 20 to get the final answer shown above in bold.
Answer:
7.
Step-by-step explanation:
21 = 3 * 7
28 = 2 * 2 * 7
42 = 2 * 3 * 7
Collecting common factors:
t is common to all 3 sets of factors so
HCF = 7.