Question

Case123Distance328832Time4y2Speed88z

The value of y+z =

• A. 27
• B. 17
• C. 37
• D. 47

Answer 1

The correct option is A 27

Value of y

Compare case 1 and case 2, we can say speed is constant.

Distance ∝ Time (Speed is constant)

We know that, if two quantities are directly proportional, then the ratio between the two quantities is constant.

$\begin{array}{ccc}Distance& 32& 88\\ Time& 4& y\end{array}$

$\frac{32}{4}=\frac{88}{y}$

$y=\frac{4}{32}\times 88$

$y=11$

Value of z

Compare case 1 and case 3, we can say distance is constant.

$Speed\alpha \frac{1}{Time}\left(Distanceisconstant\right)$

We know that, if two quantities X and Y are inversely proportional, then the product of the two quantities is constant.

XY = Constant

$\begin{array}{ccc}Time& 4& 2\\ Speed& 8& z\end{array}$

$4\times 8=2\times z$

$z=16$

The value of y + z = 11 + 16 = 27.