WAEC 2025 · Paper 1 · Q31✱✱

If $\log_{10} x = \bar{2}.3675$ and $\log_{10} y = \bar{2}.9738$ , find $x + y$ , correct to three significant figures.

Worked solution (try it first)

$\bar{2}.3675$ means $-2 + 0.3675$ .
The antilog of 0.3675 is 2.331, so $x = 2.331 \times 10^{-2} = 0.02331$ .
In the same way, the antilog of 0.9738 is 9.415, so $y = 9.415 \times 10^{-2} = 0.09415$ .
Add: $x + y = 0.11746$ , which is 0.117 to three significant figures, option C.