# Thread: ratio and proportion

1. ## ratio and proportion

(a) Two temperatures are in the ratio 16:13. If the second temperature is 169C, what is the first temperature?

(b) Two speeds are in the ratio 8:3. If the first speed is 320Km/h,what is the second speed?

please show working out thanks

2. $16:13 = y:169$
Remember that whatever you multiply one side of the ratio by, you must multiply the other side by the same number.

$169\div13=13$, So
$y=16\times13=208$

Because both sides of the ratio have to be multiplied by $13$ to get from $13$ in ratio 1 to $169$ in ratio 2.

$16:13=208:169$

Answer: $208$

Have an attempt at the second part yourself