The product of two numbers is 3.92. If one of them is 1.40, then the other number is ____.
2.8
Let the other number be x.
1.40 × x = 3.92
⇒ x = 3.92 ÷ 1.4
⇒ x = 39.2 ÷ 14
(On multiplying both numerator and denominator by 10)
⇒ x = 392 ÷ 140
⇒ x = 2.8
∴ The other number is 2.8.