**Consider the first two ratios [ ]/45 = 16/40**

**Let us assume the missing number be P**

Then, P/45 = 16/40

**By cross multiplication we get,**

P = (16 × 45)/40

P = 720/40

P = 72/4

**Divide both numerator and denominator by 4.**

P = 18

**Therefore, [18]/45 = 16/40**

**Now, consider the last two ratios, 16/40 = 24/[ ]**

**Let us assume the missing number be Q,**

Then, 16/40 = 24/Q

**By cross multiplication we get,**

Q = (24 × 40)/16

Q = 960/16

**Divide both numerator and denominator by 16.**

Q = 60

**Therefore, 16/40 = 24/[60]**