If log

_{10}2 = 0.3010 and log_{10}7 = 0.8451, evaluate log_{10}280-
**A.**

3.4471 -
**B.**

2.4471 -
**C.**

1.4471 -
**D.**

1.4071

##### Correct Answer: Option B

##### Explanation

Log 2 = 0.3010, Log 7 = 0.8451

∴Log 280 = Log 28 x 10

= Log 7x4x10

=Log7 + Log4 + Log10

= Log7 + Log2^{2} + Log10

= Log7 + 2Log2 + Log10

= 0.8451 + 2(0.3010) + 1

= 0.8451 + 0.6020 + 1

= 2.4471