Square root of 2 times the square root of 15

400 because the square root of 2 is 4 because the square root is multiplying a number by itself so the square root of 15 is 225 which means the answer is 400 because 4 times 225 is 400

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post