Answers

The Brainliest Answer!
2015-10-11T10:04:12+08:00
NOTE: Please use as the solution the solution on bold, not on the italic one. It's more complicated. 

This is done by dividing 4 1/5 by 1 3/4.
We can convert this things on decimal to be more easy, seriously.

4 1/5 ÷ 1 3/4 = x
4.2 ÷ 1.75 = x 
2.4 = x
2 2/5 = x

So therefore, he can finish one mat in 2 days, and 4 hours.

We shouldn't convert for it to be more easy-to-understand. Instead, use the divisor's reciprocal.
4 1/5 ÷ 1 3/4 = x
21/5 ÷ 7/4 = x
21/5 × 4/7 = x
84/35 = x
2.4 = x
2 2/5 = x

So therefore, he can finish one math in 2 days, and 4 hours. 

1 5 1
I think it shouldn't be 4 hours, since 2/5 of 24 is 9.6, it's either 4 hours or 9 hours and 6 minutes. :/
I mean, in one day there is "24" hours, and 2/5 of 24 is 9.6.
But for me, it's 4 hours I think.