Directions : Given data is regarding three automatic toys on two types of…
2019
Directions : Given data is regarding three automatic toys on two types of movements: Neck movements (NM) and Hand rotation (HR). It starts recording from 9 AM onwards on 12 June. Each toy has different battery percentage and battery capacity.
Toy A: Battery Capacity = 1500 units, Battery Percent = 80%
At every 4th NM and 3rd HR together, 1 unit of battery is consumed. Toy A gets completely discharged at 11 AM.
Toy B: Battery Capacity = 2000 units, Battery percent = 75%
NM = 30/min, HR/min = 50% of NM/min of toy A. At every 3rd NM and 2nd HR together, 1 unit of battery is consumed.
Toy C: Battery Capacity = 120% of battery capacity of toy B, Battery Percent = 60% NM/min = NM/min of toy A + 5, HR = 30/min. at every 3rd NM and 2nd HR together. 1 unit of battery is consumed.
If power consumed per NM of toy B is 0.1 unit, then what is power consumed per HR of toy B on that day?
- A.
0.45 unit
- B.
0.35 unit
- C.
0.15 unit
- D.
0.2 unit
- E.
0.8 unit
Show answer & explanation
Correct answer: B
Concept
When a fixed amount of battery is consumed for a fixed bundle of actions performed together, the energy of that single unit is shared among all the actions in the bundle. If one unit of battery is drained for every group of (m) Neck Movements together with (n) Hand Rotations, then: 1 unit = (m x power per NM) + (n x power per HR). Knowing the per-NM power lets you solve for the per-HR power.
Application
For Toy B, one unit of battery is consumed at every 3rd NM and 2nd HR together. So each unit of battery covers 3 NM and 2 HR:
Energy equation for one unit: 1 = (3 x power per NM) + (2 x power per HR).
Substitute the given power per NM = 0.1 unit: 1 = (3 x 0.1) + (2 x power per HR).
Compute the NM share: 3 x 0.1 = 0.3 unit, so 2 x power per HR = 1 - 0.3 = 0.7 unit.
Solve for power per HR: power per HR = 0.7 / 2 = 0.35 unit.
Cross-check
Put the value back: (3 x 0.1) + (2 x 0.35) = 0.3 + 0.7 = 1 unit, which matches the one unit drained per bundle. Hence power consumed per HR of Toy B is 0.35 unit.