Question

6. Find the sum of whole number divisible by 3 and lies between 100 and 200.​

Answer 1

4950

Explanation:

first find the smallest multiple of 3 thats >100, 3*33=99, so 3*34=102 is the smallest multiple of 3 >100.

next find the greatest multiple of 3 <200, 3*66=198 which is the greatest multiple of 3<200

34-66+1=number of terms=33. then find the average of the terms: 102+198/2=150. 150*33=4950. the answer should be 4950

Answer 2

Explanation:

The first number in the sequence = 102

The last number = 198

The number of terms =

L = a1 + (n-1)*d

198 = 102 + (n- 1)*3 Subtract 102

198 - 102 = (n - 1)* 3

96 = (n - 1)*3 divide by 3

32 = n - 1 add 1

33 = n

Sum = (a1 + L ) * n/2

sum = (102+198)*33/2

sum = 300 * 33/2

sum = 150 * 33

sum = 4950