Answer:
Number on ants on Earth = 1.2 × 10¹⁵
Step-by-step explanation:
1 quintillion = 10¹⁸ or (1000000000000000000)
∴ 12 quintillion = 12 × 10¹⁸
12 quintillion = 10,000 × Number of ants on Earth
Let the number of ants on Earth = n
12 quintillion = 10,000 × n
dividing both sides by 10,000
12 quintillion ÷ 10,000 = n

Number on ants on Earth = 1.2 × 10¹⁵