21, 20, ?, 4, 53, -28
A.60
B.4
C.40
D.29
E.36
Sol:
21 -12 = 20
20 + 32 = 29
29 – 52 = 4
4 + 72 = 53
53 – 92 = -28
21, 20, ?, 4, 53, -28
A.60
B.4
C.40
D.29
E.36
Sol:
21 -12 = 20
20 + 32 = 29
29 – 52 = 4
4 + 72 = 53
53 – 92 = -28