Rules for SN = must be a number from 1 and less than 10 times a power of 10
So our number becomes
2.22 x 10⁸ - It takes a move of 8 places to the right to make the number 222,000,000
S1 = speed of boat 1
<span> t1 = time to do 1400 meters (boat 1) </span>
S1*t1 = 1400
<span><span>S2 </span>= speed of boat 2 </span>
1400 + S2*t1 = X
t2 = time to do X + 600 (boat 2)
S1*t2 = X + 600
S2*t2 = 2X - 600
S1 = 1400/t1
S2 = (X-1400)/t1
<span>T = t2/t1 </span>
1400*T = X + 600
X*T - 1400*T = 2X - 600
X = 3600 meters
<span> River is 3600 meters wide</span>
