IBPS SO Prelims Exam Model Paper 4

Given:
A number is divided in the ratio of 8 ∶ 12 ∶ 5.
12 is added to the first part.
18 is subtracted from the second part.
Third part is increased by 20%.
Concept used:
Here we have used the fundamental concept of ratio.
Calculation:
Let the number be 8x, 12x and 5x
12 is added to the first part = 8x + 12
18 is subtracted from the second part = 12x - 18 and
the third part is increased by 20% = 5x + 20% of 5x = 6x
Now, (8x + 12) ∶ (12x - 18) ∶ 6x = 10 ∶ 9 ∶ 6
Taking any two ratios we can find the value of x
(12x - 18) ∶ 6x = 9 ∶ 6
⇒ 6(12x - 18) = 9 × 6x
⇒ 72x - 108 = 54x
⇒ 18x = 108
⇒ x = 6
New number = 10x + 9x + 6x = 25x = 25(6) = 150