Q. Find out the wrong number:
2807, 1400, 697, 347, 171, 84, 41, 20
2807, 1400, 697, 347, 171, 84, 41, 20
✅ Correct Answer: (B)
347
Explanation: From the given figure , we can see that
First term = 2807
Second term = ( First term - 7 ) ÷ 2 = 1400
Third term = ( Second term - 6 ) ÷ 2 = 697
⇒ Second term = ( 2807 - 7 ) ÷ 2 = 1400 ;
⇒ Third term = ( 1400 - 6 ) ÷ 2 = 697 ;
⇒ Fourth term = ( 697 - 5 ) ÷ 2 = 347; 347 is wrong. It should be 346.
⇒ Fifth term = ( 346 - 4 ) ÷ 2 = 171 ;
⇒ Sixth term = ( 171 - 3 ) ÷ 2 = 84 ;
⇒ Seventh term = ( 84 - 2 ) ÷ 2 = 41 ;
⇒ Eighth term = ( 41 - 1 ) ÷ 2 = 20
Hence, 347 is wrong. It should be 346.
Explanation by: Yatendra Sir
From the given figure , we can see that
First term = 2807
Second term = ( First term - 7 ) ÷ 2 = 1400
Third term = ( Second term - 6 ) ÷ 2 = 697
⇒ Second term = ( 2807 - 7 ) ÷ 2 = 1400 ;
⇒ Third term = ( 1400 - 6 ) ÷ 2 = 697 ;
⇒ Fourth term = ( 697 - 5 ) ÷ 2 = 347; 347 is wrong. It should be 346.
⇒ Fifth term = ( 346 - 4 ) ÷ 2 = 171 ;
⇒ Sixth term = ( 171 - 3 ) ÷ 2 = 84 ;
⇒ Seventh term = ( 84 - 2 ) ÷ 2 = 41 ;
⇒ Eighth term = ( 41 - 1 ) ÷ 2 = 20
Hence, 347 is wrong. It should be 346.
First term = 2807
Second term = ( First term - 7 ) ÷ 2 = 1400
Third term = ( Second term - 6 ) ÷ 2 = 697
⇒ Second term = ( 2807 - 7 ) ÷ 2 = 1400 ;
⇒ Third term = ( 1400 - 6 ) ÷ 2 = 697 ;
⇒ Fourth term = ( 697 - 5 ) ÷ 2 = 347; 347 is wrong. It should be 346.
⇒ Fifth term = ( 346 - 4 ) ÷ 2 = 171 ;
⇒ Sixth term = ( 171 - 3 ) ÷ 2 = 84 ;
⇒ Seventh term = ( 84 - 2 ) ÷ 2 = 41 ;
⇒ Eighth term = ( 41 - 1 ) ÷ 2 = 20
Hence, 347 is wrong. It should be 346.