Refer to the following series and answer the question. (Counting to be done from left to right only.) (All numbers are single-digit numbers only.) (Left) 9 7 6 4 3 5 7 6 4 6 7 6 9 8 7 7 6 6 7 6 5 7 6 8 7 5 6 (Right) How many such even digits are there, each of which is immediately preceded by a perfect square and immediately followed by an even digit? (NOTE: 1 is also a perfect square)
None
Single-digit perfect squares: 1, 4, 9. Even single digits: 2, 4, 6, 8.
Number the positions 1 to 27: 9(1) 7(2) 6(3) 4(4) 3(5) 5(6) 7(7) 6(8) 4(9) 6(10) 7(11) 6(12) 9(13) 8(14) 7(15) 7(16) 6(17) 6(18) 7(19) 6(20) 5(21) 7(22) 6(23) 8(24) 7(25) 5(26) 6(27).
Scan for even digits and check both conditions:
Pos 3 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 4 = 4 (even): preceded by 6 (not a perfect square) ✗
Pos 8 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 9 = 4 (even): preceded by 6 (not a perfect square) ✗
Pos 10 = 6 (even): preceded by 4 ✓ (perfect square); followed by 7 (odd) ✗
Pos 12 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 14 = 8 (even): preceded by 9 ✓ (perfect square); followed by 7 (odd) ✗
Pos 17 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 18 = 6 (even): preceded by 6 (not a perfect square) ✗
Pos 20 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 23 = 6 (even): preceded by 7 (not a perfect square) ✗
Pos 24 = 8 (even): preceded by 6 (not a perfect square) ✗
Pos 27 = 6 (even): preceded by 5 (not a perfect square) ✗
No position satisfies all three conditions simultaneously: the even digit is preceded by a perfect square AND followed by an even digit.
Hence, the count is None.
Select the number from among the given options that can replace the question mark (?) in the following series.
5, 18, 39, 68, 105, ?
What will come in place of question mark (?) in the following number series?
2, 5, 11, 23, 44, 77, ?
What will come in place of question mark (?) in the following number series?
31, 32, 36, ?, 61, 86
What will come in the place of question mark (?) in the following number series?
3, 6, 18, ?, 630, 6930
What should come in place of the question mark ‘?’ in the following number series?
60, 40, 50, ?, 180, 460
A series is given with one term wrong. Select that wrong term from the given alternatives.
J12, M24, P48, S96, U192