#### Answer

Choice (b) because:
$\frac{25}{100}\times 2,000,000Cal=500,000Cal$
And since 42,000J per minute = 10,000Cal, we obtain:
$\frac{500,000}{10,000}=50minutes$

Published by
W. H. Freeman

ISBN 10:
1464108684

ISBN 13:
978-1-46410-868-6

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