Question

Missing Number
1. 1,0,3,2,5,6,?
a. 9
b. 8
c. 10
d. 7
2. 1438,1429,1417,1402,?
a. 1378
b.1384
c. 1387
d. 1392
3. 456:15 : : 789:?
a. 15
b. 16
c. 18
d. 24

Answer 1

1) Answer is 7 option d
2) Answer is 1384 option b
3)I think so is option c 18
I am not sure of third question