Question 41

Select the number that can replace the question mark (?) in the following series.
1500, 745, 370, 180, 87.5, ?

Solution

Let's assume 'y' in place of the question mark.

$$y\times2+10 =87.5$$

$$87.5\times2+5 = 175+5 = 180$$

$$180\times2+10 = 360+10 = 370$$

$$370\times2+5 = 740+5 = 745$$

$$745\times2+10 = 1490+10 = 1500$$

So $$y\times2+10 = 87.5$$

2y = 87.5-10

2y = 77.5

y = 38.75

Hence 38.75 will come in place of question mark.

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Select the number that can replace the question mark (?) in the following series.1500, 745, 370, 180, 87.5, ?