Question

Mohan spends 50 minutes running and swimming. Running burns 20 calories per minute and swimming burns 10 calories per minute.
He runs for r minutes.
Which of these expressions gives the total calories he burns in running and swimming.
a. 20+ r+ 10
b.20r + 50 * 10
c.20r +50 (10 - r)
d. 20r+10 (50 -r)
pls say fast

Answer 1

Answer:

I think answer is 20r +10 (50-r)

Answer 2

Given,

Mohan spends a total of 50 minutes running and swimming.

Calories burnt per minute:

By running = 20

By swimming = 10

Mohan runs for r minutes.

To find,

Expression for total calories burnt.

Solution,

This problem can be simply solved following the below process.

As it is given that Mohan runs and swims for a total of 50 minutes, and he runs for r minutes, so the time spent by Mohan on swimming should be

50 - r.

Now, as it is given that running burns 20 calories and swimming burns 10 calories in a minute.

So, on running for r minutes, Mohan shall burn

20*r calories, and

Since he swims for (50 - r) minutes, so, the calories burnt will be

10*(50 - r)

Now, to find the expression for total calories he burns in running and swimming, we need to add the expressions obtained above, that is,

20*r + 10*(50 - r), or

20r + 10(50 - r).

Therefore, the total calories Sohan burns in running and swimming will be 20r + 10(50 - r), option d.