To find the least number,
Which is exactly divisible by 36 and 90. We have to find the HCF of 36 and 90.
→ 36 = 2 × 2 × 3 × 3
→ 90 = 2 × 3 × 3 × 5
Then the required HCF will be,
→ 2 × 2 × 3 × 3 × 5
→ 180 (HCF)
Thus, 180 is the least number which is exactly divisible by 36 and 90.