Question

Q. ᴛʜᴇ ꜰɪʀꜱᴛ ᴀɴᴅ ᴛʜᴇ ʟᴀꜱᴛ ᴛᴇʀᴍꜱ ᴏꜰ ᴀɴ ᴀᴘ ᴀʀᴇ 10 ᴀɴᴅ 361 ʀᴇꜱᴘᴇᴄᴛɪᴠᴇʟʏ. ɪꜰ ɪᴛꜱ ᴄᴏᴍᴍᴏɴ ᴅɪꜰꜰᴇʀᴇɴᴄᴇ ɪꜱ 9 ᴛʜᴇɴ ꜰɪɴᴅ ᴛʜᴇ ɴᴜᴍʙᴇʀ ᴏꜰ ᴛᴇʀᴍꜱ ᴀɴᴅ ᴛʜᴇɪʀ ᴛᴏᴛᴀʟ ꜱᴜᴍ??!
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Answer 1

Answer:

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First term a = 10. Last term an = l = 361. Common difference, d = 9. ⇒ n = 40.

Step-by-step explanation:

(Putting Values)

361 = 10 + (n - 1)9

⟹ 361 - 10 = (n - 1)9

⟹ 351 = (n - 1)9

⟹ 351/9 = n - 1

⟹ 39 = n - 1

⟹ 39 + 1 = n

⟹ 40 = n

Now, using Sum of terms of an AP formula

S_n = n/2a + 1

Sn = 40 (10 + 361)/ 2

⟹ Sn = 40 (371) / 2

⟹ Sn = 14840 / 2

⟹ Sn = 7420

Answer 2

well it was little bit hard for me.

hope it helps you