Answer:
314 cm
Explanation:
If Keith's height is 15x and his nephew's height is 7x, we can write the following equation:
1.16 * 15x = 34 + 7x * 2 -- (We get the 1.16 from the 16% increase)
17.4x = 34 + 14x
3.4x = 34
x = 10 so Keith's current height is 1.16 * 15 * 10 = 174 cm and his nephew's height is 174 - 34 = 140 cm for a total current height of 174 + 140 = 314 cm.