Question

how many threes are there from one to hundred?​

Answer 1

Answer:

3,6,9,12,15......99

a=3, d=3

a+(n-1)d=99

3(n-1)=96

n-1=32

n=33...

Therefore there are 33 threes from one to hundred....

Answer 2

Answer:

Explanation: Clearly, From 1 to 100, there are ten numbers with 3 as the unit's digit - 3, 13, 23, 33, 43, 53, 63, 73, 83, 93 and ten numbers with 3 as the ten's digit - 30, 31, 32, 33, 34, 35, 36, 37, 38, 39. So, required number = 10 + 10 = 20. 20 times.