Question

A person of mass 70 kg wants to lose 5 kg by going up and down a 10 m high stairs. He burns twice as much fat while going up than coming down. If 1 kg is burnt on expending 7000 kilocalories, the number of times he must go up and down to reduce his weight by 4 kg is

• A. 1000
• B. 5600
• C. 22400
• D. 11200

Answer 1

Answer: (D)

11200

Answer 2

: here, mass of man =70 kg, h=10 m, g= $10 \mathrm {~ms} ^ { - 2 }$

Number of kilocalories burnt while going up and down

Once

$= \frac { 3 \times 70 \times 10 \times 10 } { 2 \times 4.2 \times 1000 } = 2.5 \mathrm { Kcal }$

Total number of kilocalories to be burnt for losing 4 kg of weight

$= \frac { 28000 \mathrm { kcal } } { 2.5 \mathrm { kcal } } = 11200$