Explanation

Find the difference between terms:  

10 - 2 = 8  

20 - 10 = 10  

38 - 20 = 18  

64 - 38 = 26  

Differences: 8, 10, 18, 26  

Now find difference of differences:  

10 - 8 = 2  

18 - 10 = 8  

26 - 18 = 8  

Next difference increases by 8 again  

So next difference = 26 + 8 = 34  

Next term = 64 + 34 = 98

Last verified on 09-07-2026

Explanation

The differences are increasing by 2:

6 → 11 (+5)

11 → 18 (+7)

18 → 27 (+9)

So the missing number is 18.

Last verified on 17-06-2026

Explanation

Look at the pattern: each term × 3  

2 → 6 → 18 → ? → ? → 486  

So 18 × 3 = 54

54 × 3 = 162  

162 × 3 = 486  

Full sequence: 2, 6, 18, 54, 162, 486  

Now "4th term from the last"  

Last = 486, 2nd last = 162, 3rd last = 54, 4th last = 18.

Last verified on 24-06-2026

Explanation

For an A.P., nth term = a + (n-1)d, where a = first term, d = common difference

Given:  

a5 = a + 4d = 18  

a15 = a + 14d = 58  

Subtract: 10d = 40 → d = 4  

Put d=4 in a + 4d = 18 → a + 16 = 18 → a = 2

Sum of first n terms = n/2 [2a + (n-1)d]  

S25 = 25/2 [2×2 + 24×4]  

= 25/2 [4 + 96]  

= 25/2 × 100 = 25 × 50 = 1250

Last verified on 13-06-2026

Explanation

6-2=4, 12-6=6, 20-12=8, 30-20=10  

Differences go 4, 6, 8, 10... next is 12  

So 30 + 12 = 42

Last verified on 13-06-2026