MHT CET20225 Aug 2022Evening ShiftMathematicsApplication of DerivativesActual
The rate at which the population of a city increases varies as the population present. Within the period of 30 years, the population grew from 20 lakhs to 40 lakhs. Then, the population after a further period of 15 years will be ( Take 2 =1.41)
Options
- A56 lakhs
- B60 lakhs
- C57.4 lakhs
- D56.4 lakhs
Correct answer
D. 56.4 lakhs
Step-by-step solution
aligned & d p d t p d p d t =k p d p p = k d t & _e P=k t+C aligned Putting t =0 year and p =20 lakhs We get c = _ e 20 _e P=K t+ _e 20 Again putting t =30 years and P =40 lakhs aligned & _e 40=K 30+ _e 20 & K= _e 2 30 & _e P= _e 2 30 t _e 20 aligned Putting t =45 years We get _e p= _e 2 30 45+ _e 20 aligned & _e P= 3 2 _e 2+ _e 20 & _e P= _e 2 3 2 20 & P=2 2 20 lakhs aligned P =2 1.41 20 lakhs P =56.4 lakhs