Question

adam swam 1500m in 19 minutes. if swimming at a rate of 4.5km/h burns 600 calories, how many calories did adam burn

Answer 1

Adam burnt 631.6 calories approximately

Solution:

Given that, Adam swam 1500m in 19 minutes.  

If swimming at a rate of 4.5km/h burns 600 calories,  

we have to find how many calories did adam burn?

Now, let us find his rate of swimming

Distance travelled = speed rate x time taken

$\begin{array}{l}{1500 \mathrm{m}=\text { rate } \times 19 \text { minutes }} \\\\ {1500 \times 1 \mathrm{m}=\text { rate } \times 19 \times 1 \text { minute }}\end{array}$

We know that 1 hour = 60 minutes and also 1 kilometer = 1000 meter

$\begin{array}{l}{1500 \times \frac{1}{1000} \mathrm{km}=\text { rate } \times 19 \times \frac{1}{60} \text { hour }} \\\\ {\frac{1500}{1000}=r a t e \times \frac{19}{60}} \\\\ {\text { Rate }=\frac{60}{19} \times \frac{3}{2}} \\\\ {\text { Rate }=\frac{30}{19} \times 3} \\\\ {\text { Rate }=\frac{90}{19}=4.736 \mathrm{km} / \mathrm{h}}\end{array}$

Now, we know that, swimming at a rate of 4.5km/h burns 600 calories,

Let "n" be the calories burnt when adam swam 1500 meter in 19 minutes

$\begin{array}{l}{4.5 \mathrm{km} / \mathrm{h} \rightarrow 600 \text { calories }} \\\\ {\text {Then, } 4.736 \mathrm{km} / \mathrm{h} \rightarrow \text { n calories. }}\end{array}$

Now, by criss cross multiplication method,

$\begin{array}{l}{4.5 \times n=4.736 \times 600} \\\\ {\rightarrow 4.5 n=2842.1052} \\\\ {\rightarrow n=631.578}\end{array}$

Hence, adam burnt 631.6 calories approximately.