Rate?

[amirp]

Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

[grockit_andrea]

Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

The second ant is moving at a rate of 8/3 inch per second. The first ant's rate is 2 inches per second, which can be represented as 6/3 per second. 6/3 x 1 = 6/3, and 6/3 x 1/3 = 2/3. 6/3 + 2/3 = 8/3.
You don't really need to deal with fractions to answer this, though; you can figure out pretty easily that the first ant moves 12 inches in 6 seconds, and 12 x 4/3 = 16. The legs of the triangle are therefore 12 and 16, and the hypotenuse is 20 inches, or 1 2/3 (1.67) feet.

[GMATGuruNY]

Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

1/3 faster means 4/3 of the other ant's rate: 4/3 * 2 = 8/3.

1/3 of an inch faster would mean 1/3 inch more per second than the other ant: 2 + 1/3 = 7/3.

Is the distinction clear?

[amirp]

Thank you guys. got it.