Vijay can cover ‘D’ distance with ‘S’ speed in ‘T’ time. He can cover same…
2018
Vijay can cover ‘D’ distance with ‘S’ speed in ‘T’ time. He can cover same distance with ‘S + 10’ speed in ‘(T – 2)’ time. He can cover same distance ‘D’ with ‘S – 15’ speed in (T + 6)’ time. What can be found from the given data.
(i) time to cover 200 km with speed ‘S + 10’
(ii) distance covered in (T + 6) time with (S + 10) speed
(iii) speed by which a tunnel can be crossed in 𝑇/2 hour
(iv) Ratio between time to cover distance ‘D’ with speed ‘S’ to time to cover distance (D – 5) with speed (S + 10)
- A.
only (ii)
- B.
only (ii) and (iii)
- C.
only (i) and (iii)
- D.
all of the above
- E.
only (i), (ii) and (iv)
Attempted by 3 students.
Show answer & explanation
Correct answer: E
D = S x T = (S + 10)(T - 2) gives S = 5T - 10.
D = (S - 15)(T + 6) gives S = 2.5T + 15.
Solving gives T = 10, S = 40 and D = 400.
So (i), (ii), and (iv) can be found, while (iii) lacks tunnel length.