40% of what number is 78?
A) 195
B) None of the above
C) 109.2
D) 197
E) 31.2

195

Step-by-step explanation:

Of means multiply and is means equals

40% * number = 78

Change to decimal form

.40 * number = 78

divide each side by .40

.40 number/ .40 = 78/ .40

number =195

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.