RRB ALP CBT I 17 Feb 2026 Shift 1 Paper

Concept:Successive percentage increases are combined by multiplying the decimal factors corresponding to each increase.Explanation:An increase of $x\%$ changes a number by the factor $\left(1 + \frac{x}{100}\right)$.For $10\%$, the factor is $1 + \frac{10}{100} = 1.10$.For $20\%$, the factor is $1 + \frac{20}{100} = 1.20$.For $15\%$, the factor is $1 + \frac{15}{100} = 1.15$.The net multiplying factor for all three successive increases is:$$1.10 \times 1.20 \times 1.15$$Multiplying the first two factors:$$1.10 \times 1.20 = 1.32$$Now multiply this result by the third factor:$$1.32 \times 1.15 = 1.518$$This means the final value is $1.518$ times the original value.The overall percentage increase is found by:$$(1.518 - 1) \times 100 = 0.518 \times 100 = 51.8\%$$So the number increases by $51.8\%$ after all three successive increases.Answer:The overall percentage increase is $51.8\%$.Therefore, the correct option is A. $51.8\%$.