SSC MTS 5 Aug 2019 Shift 3 Paper

Let the value of C be 100x
⇒ B = 125% × C
⇒ B = 125x
⇒ A = 120% × B
⇒ A = 120% × 125x
⇒ A = 150x
⇒ C is less than A = 150x – 100x = 50x
⇒ Required % = $\frac{50\mathrm{x}}{150\mathrm{x}}\times 100$ =33.33%
∴ C is 33.33% less than A.
Alternate Method
Let B be 100,
A is 20% more than B,
⇒ A = 120% of B
⇒ A = 120/100 × 100 = 120
B is 25% more than C
⇒ B = 125% of C
⇒ C = B × 100/125
⇒ C = 100 × 100/125 = 80
C is lesser than A by,
⇒ 120 – 80 = 40
In percentage,
⇒ 40/120 × 100
⇒ 33.33%
∴ C is 33.33% less than A.