প্রশ্ন: 12 + 22 + 32 + ........... + 302 = ?

সমাধান:
12 + 22 + 32 + 42 + ...... + n2 = n(n + 1)(2n + 1)/6
∴ 12 + 22 + 32 + ........ + 302 = 30(30 + 1)(2 × 30 + 1)/6
= (30 × 31 × 61)/6
= 9455

Question: If A = 2, B = 4, C = 6, D = 8, E = 10 and so on, what is the meaning of following number 40, 18, 14, 10, 36

Solution:
Given,
A = 2, B = 4, C = 6, D = 8, E = 10.......

∴ Each code = Letter position × 2

So
40 ÷ 2 = 20 → T
18 ÷ 2 = 9 → I
14 ÷ 2 = 7 → G
10 ÷ 2 = 5 → E
36 ÷ 2 = 18 → R

the meaning of following number = TIGER

প্রশ্ন: 6 - 4x ≤ 14 এর সমাধান কত?

সমাধান:
6 - 4x ≤ 14
= 6 - 4x - 6 ≤ 14 - 6 [ উভয়পক্ষে (- 6) যোগ করে ]
= - 4x ≤ 8
= 4x ≥ - 8 [ উভয়পক্ষে - 1 দ্বারা গুণ করলে অসমতা চিহ্ন পরিবর্তিত হয়] 
= x ≥ - 8/4
= x ≥ - 2