RRB Group-D Model Paper 17 with answers for online practice

Let 4m be the principal.
Then SI = (7/4) × 4m – 4m
= 7m – 4m
= 3m.
Formula for simple interest
SI = (P × R × T)/100
Where P is the principal
R is the rate of interest
T is the time
⇒ 3m = (4m × R × 4)/100
⇒ 300m = 16m × R
⇒ R = 300m/16m
⇒ R = 18.75 %